RAC1 and melanoma: Patient #27, indeed, had multiple recognized melanoma drivers including BRAF p.V600K, RAC1 p.P29S, pTERT C228T and KRAS p.G12A, this latter arising at the time of progression; thus, patient #27 represents a good example of a combined intrinsic (RAC1 mutation) and acquired (KRAS mutation) resistance.