Interestingly, a recent study reported the occurrence of frequent NOTCH mutations in a rare form of breast cancer, adenoid cystic carcinoma (ACC) of the breast (<0.1% of invasive breast carcinomas), a tumor that is characterized by the absence of ER, PR, and HER2, which is considered a subtype of TNBC [391]. The gene discussed is PGR; the disease is breast carcinoma.