These findings suggest that both primiR-190 and primiR-199a1 might be useful as diagnostic and prognostic biomarkers for some PR-positive human breast cancers. More studies need to be done to fully understand the clinical implications of these two microRNAs on carcinogenesis, progression, and metastasis of hormone-responsive breast cancer, especially in women taking combined estrogen-progestin hormone replacement therapy. This evidence concerns the gene PGR and breast cancer.