BDNF and lung cancer: The aim of this study was to investigate the regulation of sE-cad levels in human lung cancer cell media by nicotine, BDNF, and/or β-AR ligands and how sE-cad can promote cell survival and block apoptosis via enhanced epidermal growth factor receptor (EGFR) and insulin-like growth factor 1 receptor (IGF-1R) signaling.