“…Direct sequencing is the first widely used method for the detection of EGFR mutation, but it lacks sensitivity and might miss 25% of positive cases 21 . Several other more sensitive techniques have been applied, including polymerase chain reaction (pcr) single-strand conformation polymorphism 22 , TaqMan (Roche Molecular Diagnostics, Pleasanton, CA, U.S.A.) pcr 23 , loop-hybrid mobility shift assay 24 , Cycleave (Clontech Laboratories, Mountain View, CA, U.S.A.) pcr 25 , pcr restriction fragment length polymorphism and length analysis 26 , matrixassisted laser desorption/ionization time-of-flight mass spectrometry genotyping 27 , peptide nucleic acid-locked nucleic acid pcr clamp 28 , Scorpions (DxS Limited, Manchester, U.K.) amplified refractory mutation system 29 , denaturing high-performance liquid chromatography 30 , single-molecule sequencing 31 , mutant-enriched pcr 32 , and Smart Amplification Process (DNAFORM, Yokohama City, Japan) 33 . These techniques not only vary in sensitivity, but also differ in terms of the detection of new and alreadyknown mutations and the comprehensive detection of deletions and insertions 21 .…”