KRAS and colorectal carcinoma: We then considered the six different CRC molecular subtypes previously identified [34], C1 (immune pathways down regulated), C2 (enriched in dMMR tumors), C3 (KRAS mutated), C4 (enriched in cancer stem cells), C5 (wnt signaling up) and C6 (enriched for tumors with a normal-like gene expression profile).