CHRNB4 and age-related macular degeneration: Cholinergic Receptor Nicotinic Alpha 1 Subunit (CHRNA1) and Cholinergic Receptor Nicotinic Beta 4 Subunit (CHRNB4), encoding two of the twelve gene subunits of the nicotinic acetylcholine receptor (Conti-Fine et al., 2000; Barrie et al., 2016), were found upregulated among the AMD meta-genes.