While the reported frequency of KRAS and BRAF mutations in female breast cancer is generally low (<5%) reference [33,34], a single sporadic MBC study showing a markedly high percentage of KRAS mutations (12%) also encouraged investigation of the mitogen-activated protein kinase (MAPK) pathway, which also interacts with the PIK3CA/mTOR pathway. The gene discussed is BRAF; the disease is breast cancer.