The risk of having elevated liver enzyme levels conferred by the combination of heavy drinking and metabolic syndrome was 6.42 [3.64–11.35] for AST, 3.88 [2.00–7.55] for ALT and 13.43 [8.35–21.60] for GGT, which were more than the sum of the two individual effects (SI: AST, 2.37 [1.20–4.67]; GGT, 1.91 [1.17–3.13]). The gene discussed is GPT; the disease is metabolic syndrome.