MAP2K1 and melanoma: We used 49 BRAF-mutant melanoma cell lines isolated from surgical specimens of patients not previously treated with BRAFV600E inhibitors, nor with any other target-specific inhibitor, to test responsiveness to BRAFV600E (PLX4720), MEK1/2 (AZD6244), dual PI3K/mTOR (BEZ235) and dual mTORC1/2 (AZD8055) inhibitors (Figure 1A).