Since the T790M-containing resistant cells are believed to grow more slowly than the sensitive cells, repopulation of tumor cells with different growth kinetics, along with restoration of EGFR-TKI sensitivity may occur after EGFR-TKI withdraw [16]; hence, many studies reported that the presence of T790M mutation is associated with a more favorable outcome among patients with acquired resistance to EGFR-TKI [13, 17, 18]. This evidence concerns the gene EGFR and neoplasm.