PCDHB1 (Protocadherin Beta 1) is a member of the protocadherin beta gene cluster, which belongs to the Cadherin superfamily and is expressed primarily in the nervous system. It encodes a cell adhesion protein containing six extracellular adhesion protein structural domains and a distinct cytoplasmic tail involved in the establishment and function of intercellular junctions. PCDHB1 plays an important role in neurodevelopment, and its aberrant expression has been associated with a variety of neurodevelopmental disorders, for example, PCDHB1 expression is upregulated in the brains of patients with Rett syndrome, which may be related to the neuropathological features of the disease. In addition, members of the PCDHB1 gene cluster are involved in neuronal self-recognition, avoidance, and connection establishment with other neurons.