Butyrate modulates apoptosis even in genetically damaged cells both via extrinsic as well as intrinsic pathways mainly by upregulation of the proapoptotic protein BAK, caspase-3-mediated cleavage of poly-(ADP-ribose) polymerase (PARP) and downregulation of neuropilin-1, the key apoptotic and angiogenesis regulator of tumor cells. The gene discussed is PROS1; the disease is neoplasm.