Last month, platinum-selling superstar Rihanna lent a helping hand in saving the life of actress Shannon Tavarez, who was diagnosed last April with acute myeloid leukemia. At the time the 11-year-old star of Broadway's hit musical 'The Lion King' was in desperate need of a bone marrow transplant.

Tavarez's diagnosis not only caught the attention of the Cover Girl spokeswoman, she also managed to receive help from hip-hop icon Curtis "50 Cent" Jackson, who reached out and assisted in finding her a bone marrow match. Coincidentally, the rapper-turned-actor is a distant cousin of the young actress and made it a priority to not only help his relative but also help leukemia patients across the nation.

Two weeks ago 50 -- alongside fellow G Unit MC, Tony Yayo -- joined the world's largest marrow donor center, DKMS and filmed a PSA (view the PSA below) urging their fans to register to save the lives leukemia patients as part of their "Get Swabbed to Save a Life" initiative.

"I think when people hear about donating bone marrow, the whole process seems complicated and a lot more difficult than it would be to actually to save someone's life," he explained. "I think people would be interested [to donate], especially if they saw me do it, because [fans] look at every blog I put up."

"So one of the things I'm interested in is being a donor at some point," he added. "70% of the people don't have a match in their family so they have to look outside. You need the help of someone you don't know."

Since joining DKMS two weeks ago Jackson has registered over 4,000 potentially life- saving donors.

In spite of the Broadway star having difficulty searching for a successful match, due to her mixed heritage of African-American and Hispanic, medical examiners were able to perform another procedure.

This week, Tavarez received an umbilical-cord blood transplant as alternative to a bone morrow transplant. The much-needed procedure was done Aug. 17 at Cohen Children's Medical Center in New York City.

For more info on how to sign up for a DKMS registration kit head over to www.GetSwabbed.org.