To explore the role of PI3K/AKT activation on cancer cell sensitivity to BRAF and MEK inhibition, we initially reviewed the association of mutations known to activate PI3K/AKT signalling (i.e. oncogenic NRAS and KRAS mutations15), with drug sensitivity data of more than 900 cancer cell lines in the Genomics of Drug Sensitivity in Cancer (GDSC) database. Here, KRAS is linked to cancer.