Since UBE2D1, as an ubiquitin-conjugating enzyme, was reported to be associated with tumor-suppressor protein p53, a key regulator in HCC carcinogenesis, we confirmed the regulation of UBE2D1 on p53 in QSG-7701, LM3 and SMMC-7721 cells. The gene discussed is UBE2D1; the disease is hepatocellular carcinoma.