Among the candidate factors regulating the 4-HNE-metabolizing enzymes AKRs, ALDHs, and GSTs, SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily a, member 4 (SMARCA4) is suggested to regulate the metabolism of 4-HNE in HCC. The gene discussed is SMARCA4; the disease is hepatocellular carcinoma.