CDKN1A and central nervous system cancer: A role for the increased expression of p21Cip1 during the induction of apoptosis was also suggested in glioma and ovarian carcinoma treated by cisplatin, in hepatocytes by bile acid, in colon cancer by C6 ceramide, and in differentiating granulocytes induced by granulocyte colony-stimulating factor.40 In beta cells, at least, p21Cip1 upregulation activated the intrinsic apoptotic pathway via BAX expression.41