DCX (doublecortin) is a microtubule-associated protein essential for cortical development and neuronal migration. During brain development, DCX regulates nucleokinesis—the nuclear translocation required for proper neuronal positioning—through its interaction with microtubules 1. DCX mutations cause type 1 lissencephaly and subcortical band heterotopia by impairing this migration process 12. Recent structural studies reveal DCX promotes α-tubulin polyglutamylation and restricts neurite branching, highlighting its role in maintaining the tubulin code 3. Beyond developmental roles, DCX serves as a marker of neuronal maturation. In adults, while DCX traditionally marks newly generated neurons in hippocampal neurogenesis in rodents and macaques, it displays atypical expression patterns in humans, appearing across diverse neuronal populations rather than defining immature cell types 4. DCX+ neural progenitors from the central nervous system can infiltrate peripheral tissues; notably, they migrate into prostate tumors where they promote neurogenesis and tumor progression, suggesting unexpected roles in cancer biology 5. Clinically, DCX expression responds to therapeutic interventions—exercise-induced cathepsin B enhances DCX expression in hippocampal progenitor cells, correlating with improved memory function 6. DCX genetic variants associate with neurodevelopmental disorders affecting intellectual disability and social behavior, potentially converging with COMT and FMR1 in Wnt signaling and axon morphogenesis pathways 7.