PGR and breast cancer: Finally, the pineal hormone further enhanced the inhibition of gene expression induced by doxorubicin, as in the case of XBP1 (a promoter of tumor invasion) [35]; WEE1 (involved in checkpoint progression) [36]; GATA3 (highly expressed in estrogen dependent breast cancers) [37]; PGR, that usually is overexpressed in estrogen positive breast carcinomas [38] and BCL-2, a pro-survival protein whose targeting enhaces vulnerability to therapy in ER-positive breast cancer [39].