CHRNA7 and cancer: Nicotine in tobacco is modified by nitrosation to form nitrosamines and the well-known tobacco-specific carcinogen, NNK, which was reported to enhance cancer progression and metastasis through α7-nAChR and to be a hallmark of the epithelial–mesenchymal transition (EMT).[12] NNK binds the β-adrenoceptor (β-AR) and induces cell proliferation and invasion in pancreatic cancer.