CEP162 (centrosomal protein 162, also known as KIAA1009) is a centrosomal and microtubule-associated protein essential for primary cilia assembly and neuronal function. Primary function: CEP162 acts as an axoneme-recognition protein that promotes transition zone assembly at the ciliary base by directly binding axonemal microtubules 1. It localizes to distal centriole ends before ciliogenesis and mediates recruitment of transition zone components, including CEP290, to microtubules 1. Mechanism: CEP162 tethers at centriole distal ends to restrict transition zone formation specifically at the cilia base; loss of this tethering causes ectopic transition zone assembly at cilia tips, generating abnormally long cilia 1. During mitosis, CEP162 localizes to spindle poles and is required for proper chromosome 6 and centrosome separation 2. Disease relevance: Homozygous truncating CEP162 variants cause late-onset retinitis pigmentosa through specific loss of ciliary function while retaining neurogenic capacity 3. A CEP162 polymorphism (rs9362054) associates with nonproliferative diabetic retinopathy susceptibility in Chinese populations 4, and this SNP shows borderline genome-wide significance in Japanese diabetic retinopathy studies 5. Clinical significance: CEP162 dysfunction represents a ciliopathy mechanism causing progressive retinal degeneration, highlighting the critical role of ciliary transition zones in photoreceptor maintenance.