BRAF and melanoma: In BRAF mutant melanoma—the BRAFV600E mutation in particular—the expression of Ca2+-ATPase isoform 4b (PMCA4b) on the plasma membrane is low compared with benign nevi and is markedly elevated by vemurafenib (BRAF inhibitor) or selumetinib (MEK inhibitor) treatment, which indicates crosstalk between PMCA4b and the MAPK pathway.