Young Son Steps Up to Help His Dad Fight Cancer at Just 9 Years Old
It’s not every day a 9-year-old is asked to donate stem cells, but when his dad was on the verge of death, that’s what young Stephen Mondek did. The son saved his dad, who had terminal cancer.
Son Saves Dad with Cancer
“It's just amazing,” said Stephen’s dad, Nick, a 48-year-old anesthesiologist who developed leukemia for the second time in his life. “I got a second chance at a second chance just to still be here because if I didn't have the transplant, things would not be good right now.”
Stephen was the only possible donor who matched with Nick and was more than willing to help his dad. He became the youngest-known stem cell donor at a Los Angeles children’s hospital by doing so.
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“I didn't want him to feel obligated or pressured,” Nick recalled of asking Stephen to get tested. “I didn't even tell him that he was basically going to be our last option.”
“We're wondering if you would like to be tested to see if you want to be a potential donor,” he asked Stephen. The boy’s response: “When do we go?”
He Was Diagnosed With Leukemia
Nick was diagnosed with leukemia in 2022. At the time, his brother donated some stem cells.
“I had a feeling that it would come back. I just didn't know when,” Nick says. “It's a very aggressive disease, and I had a few mutations that make the disease even more difficult to treat and more prone to relapse.”
“We followed every clinical protocol, but the disease still managed to come back, so we had a new problem on our hands,” said Ronald Paquette, MD, clinical director of the Stem Cell and Bone Marrow Transplant Program at Cedars-Sinai Cancer. “How could we treat his cancer a second time around and have a better chance that it doesn’t return?”
There Was No Other Option for the Dad
While he was looking for a donor, he realized he wasn’t ready to leave his family: his wife, Danielle; Stephen; and his 6-year-old, John.
Nick asked his doctor if Stephen could be a potential donor, and his doctor confirmed that he could.
“There was no other treatment available,” Nick explained.
Stephen went through several weeks of pre-donation prep. He was placed under general anesthesia, and a catheter was placed in his neck. He stayed in the ICU for over six hours while his blood circulated through a centrifuge that pulled out the stem cells.
Dad Doubts if He’s Doing the Right Thing
“That hour while he was asleep under anesthesia was probably one of the toughest periods of my life,” remembers his dad. “You just start to question everything. Am I doing the right thing?” Thankfully, Stephen says, “I wasn’t nervous at all.”
The procedure was a success, and Stephen went home the same night. After six days of chemo, Nick received the stem cell transplant.
Transplant Day
“Transplant day is always dramatic,” said Dr. Ronald. “The patient knows that they cannot survive without the stem cells, and the delivery of the stem cells into their body is like a rebirth. We call that day their stem cell birthday.”
He spent the next two weeks in the hospital recovering. His first time out of the hospital was to visit Stephen at his little league game. His family was very happy to see him there.
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“I just hope he knows what his actions can do in life, just helping another person,” Nick said. “It's an amazing feeling.”
“I felt good helping my dad,” said Stephen, who calls his dad his best friend. “It felt good to have him home.”
A Second Chance at Life
It can take over a year to know whether the stem cells will offer permanent help to Nick’s immune system.
“I'm just glad that I still get to be around and watch them grow up,” said Nick, who’s looking forward to watching the Cubs play in Chicago’s Wrigley Field with his kids.
He is a Hero
“Not all heroes wear capes,” Nick said. “Mine didn’t wear a cape; mine put on a hospital gown and donated 6 million stem cells to me.”
Now, Nick is happy to be able to enjoy time with his family and play ball with Stephen.
What a blessed family the Mondeks are. God willing, Nick will have many more happy years with them, thanks to Stephen.
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h/t: People
Featured Image Credit: YouTube/KTLA 5
Michaela Gordoni is an avid reader and part-time globe-trotter. With a bachelor's degree in International Relations and experience in the non-profit world, she has a passion for people and reporting. You can check out her portfolio here.
Originally published October 23, 2025.
