EGFR and metastatic colorectal cancer: Different studies have shown promising activity of reintroduction of anti-epidermal growth factor receptor (EGFR) drugs in patients with RAS wild-type (RAS WT) metastatic colorectal cancer (mCRC), that obtained clinical benefit by first-line therapy with anti-EGFR drugs, then became resistant and progressed to second-line treatment [1,2,3,4,5,6].