In order to clarify the conditions for the differential CDKN1A expression in HCC cells, we first detect whether JMJD5 could activate CDKN1A transcription by directly binding to CDKN1A gene locus in HCC cells, we transfected recombinant plasmids encoding the full length JMJD5 into MHCC-97H cells, and then we conducted ChIP-PCR assay with anti-JMJD5 antibody. The gene discussed is CDKN1A; the disease is hepatocellular carcinoma.