MAPK3 and melanoma: Combination of MEKis trametinib or selumetinib (AZD6244, ARRY-142886) with AZD5991 or AZD4320 was performed in all CRC and melanoma cell lines to allow comparison of BRAFMUT, RASMUT or RAS/RAFWT cells (Supplementary Table 1); combinations with the BRAFi vemurafenib (only effective in BRAFV600-mutant cells) or ERK1/2 inhibitor SCH772984 were tested in selected cell lines.