MAP2K7 and melanoma: Upregulation of the RAS/RAF/MEK signaling pathway [59, 60], an upregulation of the PI3K/Akt3 pathway via a mutation of the PTEN gene [61], a decreased expression of the retinoblastoma protein (RB) via cyclin D1 or CDK4, activating c-Kit mutations and inactivation of the CDKN2A gene can often be found in melanomas.