CHRNA7 and cancer: The neurotransmitters synthesized and released from epithelial cells and the cancers arising from them are similarly regulated, with the α7nAChR regulating serotonin [29,30] and jointly with the α3- and α5nAChRs epinephrine and norepinephrine [31,32,33] while the α4β2nAChR regulates GABA [33,34].