PDGFRA and melanoma: Pearson's correlation between gene expression CCLE data and IC50 of PLX4720 across BRAF-mutated melanomas confirmed that all seven RTK genes were directly (EGFR, AXL, EPHA2, PDGFRA and PDGFRB; r between 0.6 and 0.8) or inversely correlated (MERTK and ERBB3; r between –0.4 and –0.6) to PLX4720 resistance.