The mutation rates of EGFR in adenocarcinoma (AC), squamous cell carcinoma (SCC), and large cell carcinoma (LCC) were 40.3% (140/347), 4.4% (6/144), and 3.8% (1/26), respectively (X2 = 73.595, P<0.0005, Chi-square test, 2-sided). Here, EGFR is linked to squamous cell carcinoma.