When mediation analysis was stratified by hormone receptor status, it appeared that the association between MHT and BC risk was limited to hormone receptor-positive breast cancers: the total effect of MHT was 1.58 (0.93 to 2.64), resulting from a direct effect of 1.44 (0.85 to 2.34) and indirect effects of 1.22 (1.06 to 1.52) through PMD and 0.91 (0.78 to 0.99) through BMI. This evidence concerns the gene NR4A1 and breast carcinoma.