On his bed, David Mojica keeps a stuffed figure of Captain America.
Anyone who knows David's story and his fight to survive a life-threatening medical condition immediately makes the connection.
Captain America is not your typical superhero because he doesn't have any superpowers. But every time he's knocked down, he gets back up – with gusto. "I can do this all day," is his catchphrase.
That's resilience. And that, according to his family, friends and teachers, is David.
For a year and a half, David, 15, has faced a villain, called aplastic anemia, which is attacking his blood system.
David's bone marrow wasn't making enough blood cells for his body. His level of blood platelets – needed to form clots to stop bleeding – dropped dangerously low and put him at great risk for internal bleeding. A normal platelet count ranges from 150,000 to 400,000. Around the time of his diagnosis, David's platelet count had dropped to about 1,000.
Always an active kid before his diagnosis, David used to spend his spare time playing basketball in the backyard, or rolling through his neighborhood on a skateboard. He played the oboe in his school band.
But then in late spring of 2018, David started getting red spots on his chest and neck. His mom took him to the doctor for a blood test, which revealed he had the rare and life-threatening blood disorder.
The condition put him in constant peril of excessive bleeding of which the red spots on his skin were one sign. He was vomiting blood. He woke up with bloody blisters in his mouth. Even a tiny paper cut could make him vulnerable.
"He was getting a lot of blood transfusions, platelets," said his mother, Erica Martinez.
The diagnosis put David in desperate need of a bone marrow transplant from someone with similar genetic markers. Neither of David's two brothers was a match. His doctors conducted a broader donor search for him in registries such as Be The Match.
They came up empty.
Turns out that David's ancestry – Mexican-American – reduces his chance of finding a bone marrow donor. For David, and for thousands of patients in the U.S. with blood diseases such as aplastic anemia, leukemia or sickle cell anemia, survival depends on finding a donor with a similar ethnic background.
But for minorities like David, the odds of finding a matched donor are steep, according to Be The Match, a nonprofit that maintains the world's largest registry of potential bone marrow donors.
Of the 20 million registered donors in the Be The Match registry, most are Caucasian. The ethnic imbalance in the donor pool means the likelihood of finding a match is greatest for whites – 77%. Hispanics have 46% chance for finding a match. For African-Americans, it's just 23%, according to Be The Match.
Be The Match says the uneven distribution of donors has its roots in a myriad of factors, including language barriers and mistrust of the medical system among many African Americans that dates back decades and stems from cases such as the notorious Tuskegee syphilis experiments from 1932 to 1972.
Without a suitable donor, doctors started David on a regimen of medications to raise his blood platelet count. So far, the medications have worked and David's platelet count is back in the normal range, said Martinez.
Now doctors are beginning to wean him off the medication, which comes with its own risk. "If he relapses, he would need a bone marrow transplant to be cured," she said, adding that "a lot of people are praying" for David.
David's situation could have defeated him. But that's where his alter ego, Captain America, comes into play. The disease knocked David flat on his back. But he got back up and started fighting.
Earlier this year, he uploaded a video to YouTube and started talking about his medical journey. He also made a personal appeal for more bone marrow donors who look like him.
David decided to make the video after his doctor explained that there was a need for more people of Hispanic ethnicity to register as potential blood marrow donors.
"So I was like, more people should know about this," David said. "And I could be one of those messengers."
He didn't stop there.
Last spring, David helped organize a bone-marrow drive at Duncanville High School, where he's now a sophomore. Friends and family joined him in the effort to register donors, who have to be at least 18 years old. They signed up about 30 students during lunchtime.
Then in late October, David and his family teamed up with Be The Match to sponsor another bone marrow drive. About two dozen schools attended the marching band invitational in Duncanville, where David still plays the oboe in the school's band.
That day, more than 60 people registered, got their cheeks swabbed and submitted their samples to Be The Match.
Family is superpower
Shaunna Kile, David's English teacher who is also a Duncanville band parent, said David's superpower is his family.
His mother and his two older brothers "have rallied around one another in a way that's amazing to me," said Kile, who also knows David's older brothers, Saul Erick Padilla and Andrew Mojica, from when they were in the school band.
Last year, Saul Erick left Texas A&M, where he was a freshman, to help out. "I felt I could be here where my mom needs me and lighten her load a little," he said. Martinez works full time as a medical assistant for a doctor.
He plans to return to A&M and study genetics. In the meantime, he's taking classes at a community college.
"These guys are out there fighting for an amazing cause, and it's not just for their brother – it could be a match for anyone," Kile said.
"And yet, they're out there at these donor drives saying 'Please do this, make a difference, you can save a life.' It's just incredible," she said.
David said he visited with a family in Balch Springs, whose son also needed a bone marrow donor. "It was like they were part of the family, too, because they were going through the same thing we were."
He's fighting for them, too, and others facing the same threat.
"It's like we're a community of people who need to spread the word because what if it does happen to your son or child, or maybe you're an adult and it happens to you and you need a donor," David said.
"And it's such a blessing," he said, "if you find a match."
For more information about becoming a Be The Match donor, text the phrase Swab4David to 61474.