We demonstrated high selectivity of dabrafenib for 80% of the BRAFV600E cell lines tested and hypothesize that the relative lack of activity (gIC50>2 μM) against 3 of the BRAFV600E cell lines may be due to the presence of additional mutations (PTEN in GCT cells, PI3K in RKO cells, and p53 in A673 cells) that were confirmed by in-house sequencing. The gene discussed is PTEN; the disease is granular cell tumor.