Fig 2: Growth responses to PLX4032. (A) CellTiter-Glo® Luminescent Cell Viability Assay. Values are percent of control (DMSO) assessed at the end of 72-h treatment with PLX4032 (1 µM). Each measurement is the average of triplicate or quadruplet wells. The legend on the right provides the IC50 indicating melanoma cells that are BRAF homozygous or heterozygous for wild-type (W), V600K (K) or V600E (E) mutation. Among the BRAFWT cell strains, YUDOSO and YUFIC are heterozygous for the NRAS Q61K and Q61R mutation, respectively (dotted black line), and YUDEDE cells are null for PTEN and carry homozygous NRAS Q61H mutation (dashed black line). Green and red dashed lines indicate BRAF mutant cells null for PTEN. The horizontal dashed line marked IC50. STDV was about 5% of total count. (B) A two-sample Wilcoxon rank sum test assessing differences in growth responses of wild-type and mutant melanoma cells at several concentrations of PLX4032. The graphs, plotted as logarithm of the P-values (y-axis) over PLX4032 concentration show significant differences over a broad range of PLX4032 concentrations in the response of cells carrying the heterozygous BRAFV600E/WT alleles compared to BRAFWT melanoma cells (red), and BRAFV600E/WT compared with other mutant cells, i.e. homozygous BRAFV600E/E, BRAFV600K/K or heterozygous BRAFV600K/WT (black).