CTBP1 and lung cancer: However, discoveries that nicotine-derived carcinogenic nitrosamines are high affinity agonists for nicotinic acetylcholine receptors (nAChRs) [12,13] and β-adrenergic receptors (β-ARs) [14] have prompted investigations into the potential role of these neurotransmitter receptor families in smoking associated lung cancer initiation, progression and response to therapy.