EGFR and non-small cell lung carcinoma: Gefitinib inhibited p-EGFR but enhanced HDGF dose-dependently in tested NSCLC cells except H157 cells, which have extremely low p-EGFR and HDGF expression levels (Fig. 6D, E), indicating that gefitinib-induced HDGF elevation only occurred in EGFR-dependent NSCLC cells.