IL-21 is known to directly induce apoptosis in certain types of lymphoma.In vitro studies showed that IL-21 potently induces apoptosis of diffuse large B-cell lymphoma68, mantle cell lymphoma69,70, and chronic lymphocytic leukemia71 cells via activation of STAT3 or STAT1, leading to the altered expression of BCL2 family proteins and the activation of caspases. This evidence concerns the gene IL21 and lymphoma.