EGFR and metastatic colorectal cancer: International guidelines recommend testing for hotspot mutations in the rat sarcoma viral oncogene homolog (RAS) gene family, including the kirsten RAS (KRAS) and neuroblastoma RAS (NRAS) proto-oncogenes, to exclude RAS mutation-positive metastatic colorectal cancer (mCRC) patients from receiving anti-epidermal growth factor receptor (EGFR) therapy1,2.