GPT and colorectal cancer: As shown in Fig. 2, our analysis suggested a causal effect between liver volume and a reduced risk of colorectal cancer (the five MR methods demonstrated consistent effect directions and statistical significance with a a Benjamini-Hochberg method-corrected P value < 0.013 and did not provide evidence for causal effects of liver iron content, percent liver fat, or liver alanine transaminase levels.