PDGFRB and melanoma: Many human melanomas have mutations resulting in constitutively activated TNFα (inflammation response) [45,46], RAF-1 (CRAF proto-oncogene serine/threonine-protein kinase) [47], MEK/MAPK (mitogen-activated protein kinases) [48], PKC-α (protein kinase C alpha) [49], or PDGFR-β (platelet-derived growth factor receptor, beta polypeptide) [50].