EGFR and lung cancer: In vitro, overexpression of mutated EGFR induces morphological changes toward a mesenchymal phenotype and promotes the mobility of lung cancer cells13, implying that NSCLC patients with EGFR mutations have a higher probability of distant metastasis than do those with wild-type EGFR. Thus, first-line TT usage, which means the patients presumed to have gene aberrations, was a risk factor for initial and subsequent brain metastasis.