PCDH11X encodes protocadherin 11 X-linked, a potential calcium-dependent cell adhesion protein involved in neural development and function. This gene is part of a human-specific gene pair with PCDH11Y, created approximately 6 million years ago through a reduplicative translocation, resulting in sex-specific expression patterns where females express only PCDH11X while males express both variants 1. The protein shows strong expression in fetal and adult brain regions including neocortex, ganglionic eminences, cerebellum, hippocampus, and brainstem 1. PCDH11X demonstrates replication asynchrony in most cell types, though it shifts toward synchrony in differentiated neuronal cells, suggesting specialized regulation in neural tissues 2. Recent studies implicate PCDH11X in autism spectrum disorder pathogenesis, with the gene identified among 17 X-linked genes associated with ASD through chrX-wide association analysis 3. Additionally, PCDH11X functions in trophoblast cell migration and invasion through the PI3K/Akt signaling pathway, with dysregulation linked to preeclampsia 4. The gene has also been investigated for potential roles in atherosclerosis-related smooth muscle cell function 5. However, multiple studies have failed to establish consistent associations between PCDH11X polymorphisms and late-onset Alzheimer's disease across different populations 678.