GNRH2 and breast cancer: In a different study, GnRH2 antagonists induced apoptosis in triple negative MDA-MB-231 breast cancer cells [lack estrogen receptors, progesterone receptors, and human EGF receptor 2 (HER2)], which was mediated by p38 MAPK signaling, loss of mitochondrial membrane potential, and capsase-3 activation (23).