See, hip-hop mogul 50 Cent is a nice guy after all. Just don’t tell his nemeses Rick Ross and Fat Joe.

The tough-guy rapper, who just premiered his new film Twelve last week, recently registered as a bone marrow donor in an effort to help a young actress diagnosed with leukemia.

When 50 Cent heard that 11-year-old Shannon Tavarez needed a bone marrow transplant, he and G-Unit member Tony Yayo registered with DKMS and were added to the Be The Match Registry.

Before she was diagnosed with acute myelogenous leukemia, Tavarez had a co-starring role as young Nala in the Broadway production of The Lion King.

Tavarez’s story made 50 Cent think about his own child.

“My son is just a couple years older than Shannon and I can’t imagine if his life was needlessly cut short when there is someone out there that could save him,” the rap star said in a statement.