For example, tumors with KRAS G12C mutations exhibited higher ERK1/2 phosphorylation than those with KRAS G12D (45); to support this data, a recent study using mouse models with KRAS-mutant tumors, demonstrated higher efficacy of the MEK inhibitor selumetinib in KRAS G12C cancers compared with KRAS G12D tumors. Here, KRAS is linked to cancer.