Reduced drug sensitivity of melanomas has been associated with increased expression/activities of multi-RTKs, including epidermal growth factor receptor (EGFR), cellular mesenchymal-epithelial transition factor (c-MET, hepatocyte growth factor receptor), platelet-derived growth factor receptor beta (PDGFRB), insulin growth factor 1 receptor (IGF1R), and AXL receptor tyrosinase kinase (AXL) [127,129,130,131,132,133,134,135,136,137,138,139,140]. This evidence concerns the gene PDGFRB and melanoma.