CHRNA4 and small cell lung carcinoma: Both mouse and human SCLC NE cells express ionotropic, nicotinic cholinergic receptors (nAChR) (Fig. 2a and Extended Data Fig. 3a–c); a cholinergic agonist carbachol (CCh) elicited depolarization and widespread calcium activity in NE cell cultures (Fig. 2b, Extended Data Fig. 3d–f and Supplementary Video 4), and the evoked single-channel openings demonstrated amplitudes and lifetimes consistent with those reported for nAChRs (Fig. 2b).