Circulating levels of ALT, TBIL, ALB, and AST were inversely associated with lung cancer risk [Model 2: HR (95% CI) = 1 (Ref), 0.89 (0.73–1.08), 0.81 (0.66–0.99), 0.73 (0.58–0.92), and 0.67 (0.51–0.88) for ALT groups; HR (95% CI) = 1 (Ref), 0.88 (0.78–1.00), 0.83 (0.73–0.96), 0.83 (0.71–0.97), and 0.72 (0.60–0.85) for the TBIL groups; HRs (95% CI) = 1 (Ref), 0.85 (0.70–1.04), 0.71 (0.58–0.86), 0.65 (0.53–0.79), and 0.55 (0.43–0.72) for ALB groups; HR (95% CI) = 1 (Ref), 0.67 (0.51–0.89), 0.60 (0.45–0.79), 0.51 (0.37–0.71), and 0.69 (0.42–1.14) for AST groups (Figure 1 and Table 2)]. Here, GPT is linked to lung cancer.