…we performed mutational profiling of exons 18-24 of EGFR in tumors from 10 patients who demonstrated a partial response or marked clinical improvement (defined in Supporting Text) when treated with the drug as a single-agent at the Memorial Sloan-Kettering Cancer Center....Four of the exon 19 deletion mutations were the same as the previously described del E746-A750 (17, 18), and two were not previously described (del L747-S752 and del E746-T751insI)....Characteristics of patients sensitive to gefitinib (G) and erlotinib (E).