EGFR and esophageal squamous cell carcinoma: The phase II study of Icotinib in esophageal cancer learned lessons from the gefitinib and erlotinib studies, subjects enrolled were ESCC with EGFR overexpression (an immunohistochemical [IHC] staining score of 3 matriculations) or EGFR gene amplification (a positive fluorescence in situ hybridization [FISH] result), and the ORR increased to 16.7% (9/54); however, median PFS is only 1.7 months, with a median OS of 5.1 months.