CEP20 (centrosomal protein 20) is a centrosomal protein essential for cilia biogenesis and cell cycle regulation. Functionally, CEP20 is required for PLK1 recruitment to centrosomes and S phase progression 1, and it plays a critical role in cilium assembly as a component of centriolar satellites 2. Mechanistically, CEP20 regulates microtubule dynamics; its depletion inhibits microtubule polymerization and reduces cell proliferation and migration in lung cancer cells 3. At the molecular level, CEP20 undergoes phosphorylation at Ser46 by PLK1, enabling binding to CCDC116 and centrosomal recruitment to drive centriole overduplication 4. Disease relevance includes association with centrosome amplification and hepatocarcinogenesis when dysregulated by dietary carcinogens 4, and upregulation in non-small cell lung cancer correlating with invasion and metastasis 3. CEP20 is also implicated in developmental disorders; deletions or duplications of chromosome 16.11 encompassing CEP20 are associated with congenital malformations including cardiovascular anomalies and lateral ventricular widening 5, and rare variants have been identified in Joubert syndrome patients with posterior fossa malformations 6. These findings establish CEP20 as a centrosomal regulator linking normal cell cycle control to cancer progression and developmental disease pathogenesis.