PCDHB16 is a calcium-dependent cell adhesion molecule primarily localized to postsynaptic compartments in the mammalian central nervous system 1. The protein shows restricted expression in specific neuronal subtypes, particularly in the cerebellum, hippocampus, and cerebral cortex, with evidence for roles in photoreceptor outer segments and connecting cilia 1. PCDHB16 is proposed to contribute to synaptic connectivity specification and neuronal network organization, consistent with the broader clustered protocadherin family's function in allocating neuronal surface codes 1. Dysfunction of PCDHB16 has been implicated in neurological disorders. In partial monosomy 21 mouse models, disrupted PCDHB16 expression correlates with motor coordination deficits, spatial learning and memory impairments, and growth retardation through dysregulation of cell adhesion pathways 2. Additionally, altered PCDHB16 DNA methylation levels have been associated with both α-particle radiation-induced cellular damage 3 and type 1 diabetes susceptibility in discordant monozygotic twins, suggesting epigenetic dysregulation may contribute to disease pathogenesis 4. These findings support PCDHB16's critical role in establishing neuronal connectivity and indicate that epigenetic modifications affecting this gene may represent a mechanism linking genetic susceptibility to complex diseases.