In these analyses, there was strong evidence (P < .002; .05/21 unique adiposity-cancer pairs) for a causal effect of SHBG on endometrial cancer risk (IVW OR = 0.83, 95% CI = 0.76 to 0.90) and endometrioid endometrial cancer risk (IVW OR = 0.82, 95% CI = 0.74 to 0.89), fasting insulin on endometrial cancer risk (IVW OR = 2.75, 95% CI = 1.58 to 4.78) and endometrioid endometrial cancer risk (IVW OR = 3.08, 95% CI = 1.57 to 6.01), and HDL cholesterol on triple-negative or basal-like breast cancer risk (IVW OR = 1.16, 95% CI = 1.06 to 1.26). This evidence concerns the gene INS and endometrial cancer.