While genetically predicted C-reactive protein levels were not significantly associated with overall breast cancer liability in the IVW MR, they were nominally significantly positively associated in the MR-Egger (OR: 1.12, 95% CI: 1.01–1.23) and MR-PRESSO (OR: 1.07, 95% CI: 1.02–1.11). This evidence concerns the gene CRP and breast cancer.