This is of special importance as patients with KRAS and NRAS mutations do not respond well to EGFR inhibitors panitumumab and cetuximab35, which may mean that patient CRC-005 that exhibited an EGFR amplification in the metastasis but also carried an ARHGEF33 mutation, may not respond to EGFR inhibitor therapy. The gene discussed is ARHGEF33; the disease is colorectal carcinoma.