Interestingly, while KLF15 has been recently proposed to be a tumor suppressor in breast cancer (58) and silencing this transcription factor results in a fitness advantage for the tumor, Notch-4 is a potent breast oncogene, overexpressed in TNBC (59) and Notch signaling is involved in mammary gland tumorigenesis (60). The gene discussed is KLF15; the disease is breast cancer.