PHILADELPHIA (WPVI) -- Clara de Groot of South Philadelphia said that slime wasn't always a family favorite.
"Slime was banned from my house because I would, like, make it in my closet," Clara said.
But after the 12-year-old was diagnosed with leukemia in February, slime slid to the forefront.
It helped Clara relax.
"It's kind of like a stress ball," she explained.
Clara is in her third round of chemotherapy at Children's Hospital of Philadelphia.
She lives at the hospital for more than a month at a time, which would be difficult for anyone, let alone a child.
"I told my dad once that it's kind of like a hard job, except you can't go home for a really long time. You just got to keep working, so that's just how I think of it," Clara said.
Slime started as a distraction but has turned into a passion.
Clara started a business called 'Slimes of Courage', complete with a website, Facebook page, and Instagram account.
Clara said any profits from the slime sales go back to help other families at CHOP.
Dr. Anne Reilly, the medical director of Oncology and an attending physician with the Cancer Center at CHOP, commended Clara's efforts.
"It's really, really hard," Reilly said. "Most kids would be thinking about themselves, and I think she's really thinking about what can she do."
Clara's parents, Ben and Kristen de Groot, have helped by hauling gallons of glue and other ingredients to make slime varieties like 'grapefruit' and 'ooey gooey bubble gum.'
"Even when she's feeling her worst she's like, 'I got to make slime!'" Kristen said.
For Clara, slime equals smiles. She hopes to bring that joy to other children.
The South Philly girl also started making slime kits to help other kids in the oncology unit pass the time.
Her parents are proud of her mission.
"The fact that she's able to think of other people through this stuff," Ben said.
Her mother summed it up, "She's just incredible."
To buy the slime or donate to Clara's Mission CLICK HERE
South Philly girl battling cancer makes and sells slime to benefit other children