AXL and melanoma: It should be further noted that a similar positive correlation between the MITFlow/AXL high state, PDGFRB high expression, and acquired resistance to MAPK pathway targeted inhibitors in both BRAF (e.g. SKMEL28) and NRAS (e.g. SKMEL2) mutated melanoma cell line has been previously observed (Müller et al., 2014).