NRAS and glioblastoma: By applying the same ‘exclusivity analysis’ to mutation data from other tumor types, however, we identified or confirmed other pairs of mutations—mutant KRAS and BRAF in COAD, mutant EGFR and NF1 in GBM, and mutant BRAF and NRAS in SKCM (Petti et al., 2006; Sensi et al., 2006)—that may be synthetically lethal in those tumors.