Programmed cell-death or apoptosis, a key mechanism in cancer therapy, can be also induced by VitD through repressing the expression of anti-apoptotic proteins such as Bcl2 and Bcl-X, as well as by inducing the expression of pro-apoptotic proteins such as BAX, BAD, and BAK49, 50, 51, 52. Here, BCL2 is linked to cancer.