EGFR and cancer: Among 85 patients with EGFR-positive SQ cancer, subtypes were exon-19 deletion (33 patients [38.8%]), exon-21 L858R substitution (21 patients [24.7%]), T790M (8 patients [9.4%]), exon-20 insertion (7 patients 8.2%), and other EGFR variants (16 patients [18.8%]) (eFigure 1 in Supplement 1).