CDKN1A and hepatocellular carcinoma: KLF6 is a putative tumor suppressor in prostate, colorectal, hepatocellular carcinomas and glioblastoma.11, 12, 13, 14, 15, 16, 17 Deletion of the chromosome region containing KLF6 (10p15) has been reported in glioblastoma,16 whereas mutation analyses of the KLF6 coding region have been controversial.16, 18, 19, 20, 21, 22 KLF6 has been proposed to perform its tumor suppression function by promoting G1 cell cycle arrest mainly through cyclin-dependent kinase inhibitor 1A (CDKN1A) promoter transactivation.15