In phase 3 trials in advanced BRAFV600E/K mutant melanoma, the incidence of rash is substantially lower with the combination of the BRAF-inhibitor dabrafenib and the MEK-inhibitor trametinib (all-grade 28%) as compared to trametinib monotherapy (all-grade 57%), at the same trametinib dosing [7,8]. The gene discussed is MAP2K7; the disease is melanoma.