We analyzed 100 tumor samples from 44 patients (median progression free survival or PFS = 145 days; range = 84 to 489) (Table 1; Fig. 1A; Supplementary Fig. S1 and Table S1) whose melanomas developed acquired resistance to either vemurafenib or dabrafenib monotherapy....Also, over-expression of PIK3CA D350G and E545G, as well as the positive control mutant PIK3CA E545K, conferred vemurafenib resistance when compared to the vector or PIK3CA wild type.