According to the environment‐gene interaction formula [OReg > (OReg' × ORe'g)],32 there was evidence of multiplicatively interactive effects of causes and ADAMTS4 genotypes on HCC risk [ex., 6.90 > (1.76 × 1.03) for AFB1 interacting with ADAMTS4 haplotypes]. The gene discussed is ADAMTS4; the disease is hepatocellular carcinoma.