Fig. 2

Screening for EGFR exon 19 deletions and the T790M resistance mutation in two independent tumors (right versus left upper lung lobe) diagnosed synchronously. a Fragment-length analysis and Sanger sequencing demonstrating two different EGFR deletions in the two independent tumors. b SNaPshot analysis showing simultaneous emergence of the T790M resistance mutation in the two tumors after completion of EGFR TKI therapy