Rihanna is lending her voice to support DKMS, the largest bone marrow donor center in the world with more than two million registered donors, in their bid for a $250,000 grant from Pepsis Refresh Project. Check out the trend-setting, globetrotting singers PSA to learn more about why shes getting behind this cause. To date, 19,000 DKMS donors have helped save lives by donating their bone marrow, but they need more donors if theyre going to continue to make more life-saving matches. Want to get involved? Vote for DKMS by April 30 (you can vote daily!), and they could win Pepsis challenge.