We selected 18 patients whose cytological specimens (including adequate cancer cells) or frozen cell pellets were available from among patients diagnosed with NSCLC positive for major activating mutations of EGFR [L858R or deletions in exon 19 (Ex19 del)] at Kyushu University Hospital between October 2002 and December 2012. Here, EGFR is linked to non-small cell lung carcinoma.