Odds ratios (ORs) and 95% confidence intervals (CI) for the association between breast size and overall breast cancer risk, ER-positive breast cancer risk, and ER-negative breast cancer risk based on the different Mendelian randomization approaches used in this study. *Value based on causal effect estimate from MR-Egger regression; corresponding MR-Egger intercept value testing presence of directional (bias inducing) pleiotropy not shown.