Two cell lines had Q209L mutation (92.1, Mel202), while Omm1.3 and Mel270 had Q209P mutation….As shown in Figure 1A, the GNAQQ209L/P cells exhibited dose dependent decrease in cell viability at nanomolar concentrations (IC50<0.1 μM). The BRAFV600E cells were the most sensitive, with IC50<0.05 μM, while cells without either BRAF or GNAQ mutations exhibited little sensitivity, with IC50 >1 μM. This corresponded to inhibition of pERK with selumetinb in the sensitive mutant cells (Fig. 1B and Supplemental Fig. 1A)...