CHRNA4 and non-small cell lung carcinoma: Previously, we reported that nAChR, tropomyosin receptor kinase B TrkB, and β-AR, lead to regulation of epidermal growth factor receptor (EGFR) and the insulin-like growth factor 1 receptor (IGF-1R) in NSCLC, affecting PI3K/AKT signaling and chemoresistance [34].