CHRNA7 and non-small cell lung carcinoma: Nicotine-specific nitrosamines, including N′-nitrosonornicotine (NNN) and 4-(metylnitrosamino)-1-(3-pyridyl)-1-butanon (NNK) have the most carcinogens in cigarette smoke, which in turn after binding to α7nAChR and nicotinic acetylcholine receptors (β-AR) (e.g., adrenaline and noradrenaline) activate the EGFR/serine-threonine kinase (EGFR/Akt) signaling pathway involved in anti-apoptosis, which contributes to NSCLC progression in smokers [49].