CDKN2A and cancer: By contrast, CDKN1A and CDKN2A encode p21Cip1 and p16Ink4a, respectively, which are potent cell-cycle inhibitors in MCL [19,20], whereas FHL1 has been revealed to induce G1 and G2/M cell-cycle arrest by activating CDKN1A in human cancers [21,22].