Genetic evidence for potential molecular mediators underlying the causal relationship between obesity and breast cancer: a two-step, two-sample Mendelian randomization study

Chronic low-grade inflammation is a vital pathway linking genetically predicted BMI to breast cancer risk. Genetically predicted BMI is associated with higher genetically predicted CRP levels, potentially through a pathway involving reduced IGF-1 levels, which may attenuate the inverse association between genetically predicted BMI and breast cancer risk.