Early examples include point mutations in the ER and the AR in treated breast and prostate cancer patients, respectively, in the epidermal growth factor receptor (EGFR) in non-small-cell lung cancer (NSCLC) patients, and in kinases of the rapidly accelerated fibroblast (RAF)/mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) pathway in melanoma patients [23,24,25,26,27,28,29,30,31]. Here, EGFR is linked to melanoma.