NAV3 (neuron navigator 3) is a microtubule-associated protein that plays critical roles in cytoskeletal organization and cellular processes. NAV3 functions as a microtubule plus-end tracking protein that stabilizes microtubules and regulates microtubule dynamics 1. The protein is essential for neuronal morphogenesis, with expression throughout the nervous system in postmitotic neurons 1. NAV3 demonstrates context-dependent effects on cell migration, promoting invasion in glioblastoma cells while generally regulating cellular motility 2. In disease contexts, NAV3 acts as a tumor suppressor in multiple cancer types, including endometrial cancer, uterine leiomyomas, and colorectal cancer, where copy number losses and decreased expression are associated with tumor progression 345. Pathogenic variants in NAV3 cause neurodevelopmental disorders characterized by intellectual disability, microcephaly, and behavioral abnormalities, with affected variants impairing the protein's microtubule-stabilizing function 1. NAV3 is also associated with autism spectrum disorders, where rare inherited loss-of-function variants confer moderate risk 6. Additionally, NAV3 contributes to kidney fibrosis through a SOX9-NAV3-YAP1 signaling axis that regulates myofibroblast activation 7.