EGFR and non-small cell lung carcinoma: Zhou et al. (2014) found that miR-34a rescued hepatocyte growth factor-induced gefitinib resistance in EGFR mutant NSCLC cells by inhibiting activity of the PI3K/Akt pathway. Zhao et al. (2017) also demonstrated that combined miR-34a mimics and EGFR-TKIs synergistically sensitized both EGFR wild-type and mutant NSCLC cells. The hypermethylation of miR-34a promotor was mediated by several DNA methyltransferases (Dnmts), including Dnmt1, Dnmt2, and Dnmt3a (Peng et al., 2015, 2017; Wang et al., 2016; Lewinska et al., 2018).