When mediation analysis was conducted stratifying by hormone receptor status, it appeared that the association between MHT and BC risk was mainly due to hormone receptor-positive breast cancers: the OR of hormone receptor-positive BC associated with current use of MHT was 1.81 (1.05 to 3.10); when PMD was added into the model, the OR became 1.46 (0.84 to 2.57), which corresponds to a 36% mediated effect on the log scale. This evidence concerns the gene NR4A1 and breast carcinoma.