CDKN1A and neoplasm: It has been reported that p21Cip1/Waf1 plays an anti-apoptotic role via an increase of both p14ARF (ARF tumor suppressor) and p53 levels, and an alteration of the BCL2 Associated X (Bax)/B-cell lymphoma 2 (Bcl-2) ratio [52], inhibition downstream of caspase cascade [51,53].