KRAS and neoplasm: Confirming recent data indicating multiple mutations within the same pathway [4, 6], we identified 13 samples with concomitant mutations in two genes (Figure 3): three cases in BRAF and NRAS, five in BRAF and KRAS, and five in NRAS and KRAS. In all patients, the co-existing mutations had different VAFs, thus supporting the occurrence of tumor subclones.