EGFR and non-small cell lung carcinoma: In another large study (755 NSCLC patients, EGFR testing was less successful in samples with low (<2 ng/μl) compared to those with high DNA concentration (70 vs. 96 %, respectively), with the corresponding EGFR positivity of 13 and 9.2 %, respectively (Leary et al. 2012).