CHRNA4 and Anxiety: Polymorphisms in the human CHRNA4 gene, which encodes the α4 nAChR subunit, has been linked to anxiety and emotional lability (Markett et al., 2011), and α4β2 nAChRs have been linked to anxiety in a number of studies (McGranahan et al., 2011; Mineur et al., 2023).