Photo by Lisa Helfert

The party was, by all accounts, a blast. Kids plunged into foam pits. Moms jumped on trampolines. Dads played dodgeball. Pizza was the main course; for dessert, almost everyone devoured a slice of the baseball-themed cake. The birthday boy, Michael Mosier, preferred his Grandma Nancy’s chocolate chip cookies, but he’d insisted that his parents also get a cake for his friends. It was Aug. 24, 2014, three days before his sixth birthday, and despite a little redness in his right eye that a few people noticed but didn’t fret over, he was the epitome of a healthy young boy having the time of his life.

Ten days later, on Sept. 3, Michael’s parents, Jenny and Mark, found themselves at Children’s National Hospital in Washington, D.C., waiting for the results of their only son’s brain scan.

“I remember them saying the MRI was going to take 45 minutes, and he had been in the MRI for three or four hours,” Mark, 46, says. “At that point I thought they have to be seeing something.”

The radiologist was the first to meet with them. “He took us into this little room and he said there’s a mass on the brain,” says Jenny, 41. “It was an out-of-body experience. I still say that day is even worse than the days that would come, because it changes everything. I was terrified because I thought he was going to have brain surgery. That’s so scary. How horrible. So I said, when will he be getting surgery? At that point they kind of look at you, and it’s like, well, you need to talk to the other doctors. It became clear very quickly that there is no surgical option.”

Jenny and Mark had never heard of diffuse intrinsic pontine glioma, a tumor in the brain stem, a portion of which controls essential functions like breathing, swallowing, eye movements and balance. DIPG. Four seemingly innocuous letters that spell almost certain death for a child. In this case, their son, Michael.

Michael, pictured at age 5, enjoyed reading, baseball and art. Photo by Freed Photography

It’s late September 2020, and Jenny and Mark are recounting one of the darkest days of their lives while sitting at a conference table in a Potomac office suite, headquarters of the Michael Mosier Defeat DIPG Foundation. The couple started the nonprofit after their firstborn child died—less than nine months after that birthday party at Sky Zone Trampoline Park in Columbia—from a pediatric cancer so insidious that doctors and researchers describe it as “infiltrating” the brain.

The walls of the office are painted yellow, Michael’s favorite color. His photo adorns flyers and handouts that are piled everywhere. On one postcard, there’s a picture of Michael before he got sick, grinning and flashing two thumbs up to the camera, and one of him after his diagnosis, his face so swollen from steroids that he’s almost unrecognizable.

From Michael’s plight, the Bethesda couple has managed to find meaning. The foundation they started in 2015 to honor him has raised awareness about DIPG—and $7.8 million as of this past October. From 2017 to 2019, Jenny says, the nonprofit and its partner organization provided about a quarter of all funds in the U.S. that went toward studying the disease. The government, private industry and charities spend more than $10 billion a year on cancer research in the U.S., but only $3 million to $5 million of that—most of which comes from charitable foundations—goes toward DIPG, according to the Mosier foundation.

“I’m constantly struck by how families take what is a very difficult situation and find a way to spread knowledge and love,” says Dr. Lindsay Kilburn, a neuro-oncologist with the Center for Cancer and Blood Disorders at Children’s National. She was one of Michael’s doctors. “The Mosiers are a tremendous example of that. The amount of money they have raised to fund cutting-edge research is tremendous. They very quickly became a leader in making a true impact on a national and international level.”

Jenny, who is the full-time executive director of the foundation, and Mark, the chair of its board of directors, have become staples in the DIPG community. When Michael was diagnosed, Jenny didn’t know any other DIPG families. Now, she says, it feels as if she speaks every week with a parent whose child is suffering from the disease.

The Mosiers at Kidville to celebrate Lila’s second birthday in March 2014. Courtesy photo

“You meet a family and you get to know them and a child early in their diagnosis, and then you walk with them through the tragedy that will unfold with their child deteriorating before your eyes until they pass away,” she says. “It does to some extent force you to relive certain aspects of what we went through with Michael. That takes a toll, and definitely weighs heavily on us emotionally. [But] I’m able to focus my emotional energy on the positive of knowing that what we are doing is truly changing the landscape and the options and the hope for [these] families.”

When Melissa Overton’s son, Jack, was diagnosed in 2018, Jenny reached out. “Because of her foundation, we have hope, which is something that I cannot fathom another family in our shoes not having,” says Overton, who lives in Howard County. “Not knowing that there’s an organization that’s working to find a cure, it would be such a hopeless situation.”

DIPG kills 200 to 400 children in the U.S. each year, which makes it the leading cause of death from pediatric brain cancer, the deadliest cancer among children. Those who are diagnosed with DIPG are usually between the ages of 4 and 11. Ninety percent of kids die within two years, and the five-year survival rate is less than 1%. Unlike with most pediatric cancers, a child who is diagnosed with DIPG today faces the same prognosis as a child diagnosed 40 years ago, according to the foundation.

“One of the most moving and heartening things is that some of our very biggest supporters did not know Michael, did not know us,” Jenny says. “You find that people get invested and feel passionately. People remember that we, too, did not have a child with cancer on Sept. 3, [2014]. I guess we did, but we didn’t know.”

Michael was an inquisitive little boy who could read and write by the time he was in kindergarten. Some of his favorite books involved the human body, and The Magic School Bus, an animated children’s science show, was must-see TV for him. So when he underwent a biopsy and then radiation following his diagnosis, his parents explained his condition to him using language they thought he could understand.

“We said, this machine is going to be shooting lasers because there are extra cells in your brain,” Jenny recalls. “The extra cells are pushing against your nerves. He knew what nerves were. Michael was so smart and so perceptive. He was quiet for a little bit, and then he said to us, well, what about the other cells? Is it going to get those, too? We explained that they’re trying to hit only the bad cells and not the good cells.”

The Mosiers tried to avoid uttering words like “sick” or “cancer” around Michael. They used “brain tumor,” but never discussed his prognosis around him. Still, Michael began making a to-do list every morning during his treatment. This wasn’t a bucket list, his parents say; it was more a list of activities that he wanted to accomplish each day. He’d rattle them off after he woke up and have his mom or dad write them down in a small notepad. When he completed each item, one of his parents would check the box next to it. “I would try to put on something like ‘read a book,’ and if [I let him], he would add ‘play a video game’ or ‘drink a milkshake,’ ” Mark says. He always let him.

Even at such a young age, the son of two accomplished attorneys knew how to stand his ground. “If there was something we needed to do, we needed to get it on the list,” says Jenny, who grew up in Howard County. “If it was take a shower, you better get it on the list, or he might not do it that day because it wasn’t on the list.”

Mark and Jenny met in law school at the University of Chicago in 2001. Jenny started in private practice before becoming deputy chief of staff and counselor to Attorney General Eric Holder during the Obama administration. Mark, who’s from Kansas and played minor league baseball in the San Francisco Giants organization, is a former law clerk to Supreme Court Chief Justices William Rehnquist and John Roberts. He’s now a partner at the D.C. firm Covington & Burling.

Kids line up for a 1K fun run at the 3rd Annual Defeat DIPG Superhero Sprint & 6K on May 27, 2018. Courtesy photo

Michael was born on Aug. 27, 2008, the couple’s second wedding anniversary. Their daughter, Lila, arrived more than three years later. “From the moment Michael was born, it was clear that he had a really strong will and personality. In a good way,” Jenny says. “He was with kids from a really early age because he went to day care when he was about 6 months old. He made friends really easily.”

Rhian O’Connor was one of his closest pals. The two played Monopoly and Mouse Trap together. “He was [the] nicest kid I knew,” says Rhian, 12. “He was always up to play games, and he always included his sister and me in everything. I think about him almost every day because he was such a huge part of my life.”

Jenny is Jewish and Mark is Christian; the Mosiers celebrate multiple religious holidays. When they were looking for a synagogue to join, Jenny took Michael to a tot Shabbat service. “It wasn’t a huge crowd, maybe 30 or 40 people, and the rabbi says to the group, ‘We have an important holiday coming up.’ It was in August, I think. ‘Can anyone tell me: What is the most important holiday?’ Michael, as always, shoots up his hand and says, ‘Christmas!’ ” An athletic child who loved baseball, Michael also was into art. Several of his projects still hang throughout the Mosiers’ home. “Michael made this tree with branches with all of our names on a leaf, and then he put them on all the branches,” says Lila, now 8. “He made me and Mom’s names on leaves pointing down, and he and Dad’s names go on top and point up.”

“He said boys were the best,” Mark says, smiling.

“It was kind of rude,” Jenny says with a laugh.

The family led a charmed life until August 2014, when they noticed the redness in the corner of Michael’s right eye. They had just returned from the beach, so his parents thought his eye might be irritated from the sand or salt. But one day while he was playing soccer with his mom in their basement, a few days after his birthday party, Michael complained of double vision. “I scored a goal on him, and I was cheering because he usually did better than I did,” Jenny says. “He said, Mommy, you wouldn’t have scored except that I went after the wrong ball.”

When they went to the doctor, one side of Michael’s face was drooping. Visibly concerned, his pediatrician sent them to a pediatric ophthalmologist. After examining Michael, the eye doctor told them to go directly to the emergency room at Children’s National. Jenny didn’t even stop at home.

Michael with his sister, Lila, on a family trip to Disney World three months after his diagnosis. Courtesy photo

Scientists know there is a particular mutation that occurs in the cells that cause DIPG, but they don’t know when, where or why these tumors form at a specific point in a child’s development, says Dr. Michelle Monje, associate professor of neurology at Stanford University and a member of the Michael Mosier Defeat DIPG Foundation’s scientific advisory council. “This cancer, unlike many other kinds of cancer, can’t be surgically [treated] because it intertwines intimately with the brain,” she says. “Not only is this tumor infiltrating the normal brain stem, it’s forming connections with the normal neurons. So it’s actually integrated. It’s this really intrinsic cancer that you can’t cut out. Our traditional ways of fighting cancer with chemotherapies and radiation just don’t effectively target this cancer’s vulnerabilities.”

Radiation is the standard treatment path, but it usually only mitigates a child’s symptoms for a few months before the tumor grows back. Michael underwent 30 radiation treatments, which caused side effects like vomiting, but his tumor didn’t shrink.

The Mosiers understood the reality of their son’s prognosis, so they focused on making every day as fun as possible for him. Michael loved Disney, so the family took two vacations to Disney World, one of which was sponsored by the Make-A-Wish Foundation. They went out for toasted marshmallow milkshakes. Mark became a bit of a gamer.

“I got good at Minecraft,” he says. “It got to the point where I was playing Minecraft and he was sitting next to me telling me what to do. After a couple of weeks, I started getting addicted. I don’t know if I’ve ever seen Michael laugh harder than when he made each of the grandparents race each other on Mario Kart. He laughed so hard at Grandma Lynn going the wrong way on the track.”

Within six weeks of being diagnosed, Michael lost his ability to walk. The side effects of the steroids caused his personality to become volatile and his appetite voracious. His weight went from 44 pounds to 75 pounds before he lost the ability to see clearly, speak or eat. At the end, all he could do was blink. His parents brought in hospice care.

Michael died at home on May 17, 2015. A month later, Mark returned to work and the couple filed the paperwork to start the foundation. “There was such a feeling that we wanted to fight back,” Jenny says. “It’s the most horrible feeling to not be able to identify anything you can do to help your own child. Over the course of his illness, as my frustration and despair grew over the fact that there wasn’t anything we were going to be able to do, channeling that energy into something that could have a tangible effect grew and grew over time. I loved my career, but ultimately I made the decision that if we wanted to pursue this, I wanted to be able to put my all into it and do it full time.”

About a year after Michael’s sixth birthday party, Jenny resigned from the Justice Department.

At age 6, Michael underwent 30 radiation treatments over the span of about seven weeks, but the tumor in his brain didn’t shrink. The family celebrated his last day of radiation in November 2014. Courtesy photo

When the Michael Mosier Defeat DIPG Foundation held its first Superhero Sprint & 6K at Westfield Montgomery mall in 2016, Jenny wasn’t sure anyone would show up. To her delight, 750 people did, and the foundation raised more than $127,000. Last year’s fifth annual event, held virtually in May due to the pandemic, attracted over 2,500 participants and raised roughly $200,000.

The foundation has a network of five chapters throughout the U.S. Through one of them, it received an anonymous gift of $1 million. In 2017, the organization began partnering with the ChadTough Foundation, a Michigan-based nonprofit that honors Chad Carr, who died of DIPG in November 2015 at the age of 5. Between 2017 and 2019, the two foundations jointly granted $6.1 million to 23 research projects at 15 institutions, including the Dana-Farber Cancer Institute, Boston Children’s Hospital and the University of Newcastle in Australia. The Mosiers’ foundation is continuing to explore ways to work with ChadTough to best achieve their shared mission of funding research for a cure. “Our goal ultimately is about changing the future for other kids,” says Tammi Carr, Chad’s mother. “We believe we’re honoring our kids with these two foundations. We want to change the future so that down the road people have a different experience than we did.”

The Mosiers are such firm believers in research breakthroughs that they donated Michael’s brain to a DIPG-specific lab at Children’s National. “My first clinical trial was in this disease,” says Kilburn, who treated Michael. “I have since been involved in many studies that have unfortunately not been able to cure this disease, but that doesn’t mean that we haven’t learned a tremendous amount. We’ve learned about the biology of this tumor, but we still have a lot to do to translate all that knowledge into a cure.”

Ensuring that researchers have the money to continue pressing forward is now Jenny’s life’s work. Almost everyone she meets asks her how she can devote so much of her heart and mind to the disease that took her son. “It’s hard, because to do the job and push the foundation’s mission the way that we want to there is a certain amount of ongoing engagement with families who are in the fight now,” she says. “Living and breathing this really devastating disease all day long, that’s required. There are definitely times when it is so emotionally taxing that it’s important to regroup and try to have a little bit of balance for us and for our family.”

Each year, the Mosiers typically go to the mountains of Colorado with Mark’s family and to Rehoboth Beach with Jenny’s. Lila plays lacrosse and soccer, and does gymnastics. Jenny has fallen in love with her Peloton, which she calls a great stress reliever. But most of her time is spent on DIPG, with the goal of making people care about the disease and getting them to donate. The foundation’s efforts were essential in making May 17—the day Michael died—DIPG Awareness Day in Maryland. She’s working to have it become recognized nationally. “Part of our grand strategy is incentivizing both new researchers and experienced researchers who maybe have been studying different types of cancers to start studying DIPG,” Jenny says. “It may be that someone who’s an expert in immunotherapy but had never studied childhood brain cancer could apply that expertise to this disease and come up with new strategies.”

But that won’t bring her son back. “In some ways, the work of the foundation is the way that I get to continue to be a mom to Michael,” she says. “The time I spend doing this work honors him and is a way to channel some of the time and energy and love that I wish I was giving directly to him.”

Jenny likens learning to live with her grief over the past five years to a permanent physical injury. “Like something on your elbow,” she says. “At first, it’s the only thing that you can think about because it’s so painful, but over time you become accustomed to having that pain. The pain is something you get used to carrying around, like a backpack of bricks. Maybe one day I will be fortunate enough to be an old grandma sitting around, but I’m still going to have pictures of my 6-year-old, and I’m still going to sleep with Michael’s stuffed Yoda.”

Mike Unger is a writer and editor who lives in Baltimore.