In addition, a study of the methylation of the ADRA1A promoter region in 160 HCC patients showed that the methylation level of the ADRA1A promoter region in the tumor tissues of HCC patients was significantly greater than that in normal tissues, and DNMT inhibitors increased ADRA1A expression in HCC cell lines. The gene discussed is ADRA1A; the disease is hepatocellular carcinoma.