Using the cis-eQTL criteria and applying a FDR correction (FDR ≤ 10%), an inverse association between genetically proxied circulating concentrations of macrophage migration inhibitory factor (MIF/MIF) and overall breast cancer risk (0.88, 0.83 to 0.94, p = 1 × 10−4) was found, compatible with the results from sensitivity analyses. This evidence concerns the gene MIF and breast cancer.