Preclinical testing in melanoma has demonstrated that PLX-4032 can inhibit the in vitro and in vivo proliferation of BRAF V600E melanoma cell lines and clinical trials of PLX-4032 have shown clinical responses in BRAF V600E melanoma with the extent of response associated with the level of inhibition of phospho-ERK [50], [53]–[55]. This evidence concerns the gene MAPK1 and melanoma.