Dose response analyses showed that all the BRAF mutant melanoma cell strains were highly sensitive to PLX4032 with IC50 in the nM range (60–450 nM), whereas BRAF wild-type cells were resistant, with IC50 2.4 μM or above (Figure 1A), consistent with published information (Tsai et al., 2008). The gene discussed is BRAF; the disease is melanoma.