DCDC2 (doublecortin domain containing 2) is a ciliary protein with pleiotropic functions across multiple biological systems. Primary function: DCDC2 regulates ciliogenesis and ciliary length 12 and inhibits canonical Wnt signaling 3. In the nervous system, DCDC2 supports neuronal migration during neocortex development and maintains episodic memory through dorsolateral prefrontal cortex expression 4. Mechanism: DCDC2 stabilizes ENO1 protein, enhancing AKT phosphorylation and promoting FGL1 expression, which facilitates immune evasion via the FGL1-LAG3 checkpoint 5. Disease relevance: Biallelic DCDC2 variants cause neonatal sclerosing cholangitis (NSC), a progressive biliary fibrosis requiring early intervention 678. Variants also associate with nephronophthisis, autosomal recessive deafness, and developmental delay 78. Common polymorphisms (rs807701) contribute to dyslexia risk 9, correlating with visuo-spatial memory and long-term memory deficits in animal models 10. Clinical significance: DCDC2 protein-truncating variants cause severe early-onset hepatobiliary disease, while missense variants present milder childhood-onset phenotypes 7. Anti-DCDC2 autoantibodies represent potential diagnostic biomarkers for intrahepatic cholangiocarcinoma 5.