In terms of overall efficacy in PDXs, we observed a similar level of inhibition to tumour volume for the BRAF/PI3K inhibitor combination on BRAF mutant cells when compared to the clinically approved BRAF/MEK combination and a significantly greater (t-test P = 0.0418) inhibition of tumour growth compared to all combinations (Fig. 3f; Supplementary Fig. S4i). This evidence concerns the gene PIK3CA and neoplasm.