POC1B (POC1 centriolar protein B) is a centriolar scaffolding protein essential for centriole assembly, stability, and ciliogenesis 1. POC1B functions as part of the inner centriole scaffold, where it forms a heterodimer with POC1A that organizes an interaction network including POC5 and FAM161A to maintain centriolar integrity 2. The protein plays critical roles in early centriole duplication, later centriole length control, and acts as a positive regulator of centriole elongation 1. POC1B is required for primary cilia formation, ciliary length regulation, and cell proliferation 1. In the retina, POC1B is essential for photoreceptor sensory cilium development and retinal integrity; knockdown causes shortened outer segments and impaired visual function 3. Biallelic POC1B mutations cause cone-rod dystrophy 20 (CORD20), characterized by selective cone photoreceptor degeneration with relatively normal funduscopic appearance but disrupted outer retinal layers on imaging 45. Patients present with decreased visual acuity, photophobia, and progressive vision loss typically between ages 18-34 years 4. Additionally, POC1B mutations have been associated with male infertility presenting as oligoasthenoteratozoospermia, with defects in acrosome and flagella formation 6. POC1B mutations identified in cone-rod dystrophy patients include frameshift variants, nonsense variants, and splice-site variants 75.