CYP19A1 and breast cancer: Ribociclib received FDA approval in March 2017, based on results from the MONALEESA-2 trial, as initial endocrine-based therapy for AI-sensitive advanced or metastatic BC, in combination with an aromatase inhibitor and then, based on results from MONALEESA-7 trial, it was also approved for the treatment of peri/premenopausal women [25,26,27,28].