UNC13B (unc-13 homolog B) encodes Munc13-2, a presynaptic protein essential for synaptic vesicle priming and exocytosis 1. The protein functions as a target of the diacylglycerol signaling pathway and facilitates synaptic vesicle maturation selectively in excitatory glutamatergic synapses 2. UNC13B collaborates with UNC13A in regulating dense core vesicle fusion and controlling the location and efficiency of their synaptic release. Mechanistically, UNC13B acts upstream of vesicle fusion by priming synaptic vesicles and participates in activity-dependent refilling of the readily releasable pool 2. The protein is highly expressed in the cerebral cortex and plays a critical role in maintaining neuronal excitability 1. Disease relevance is emerging across multiple neurological conditions. UNC13B variants are associated with partial epilepsy with favorable prognosis, where affected patients demonstrate focal seizures responsive to antiepileptic therapy despite initial frequent seizures 1. UNC13B is implicated in autism spectrum disorders and schizophrenia 2, and polymorphisms show association with diabetic kidney disease susceptibility in Asian populations 3. Additionally, UNC13A-related pathology (linked functionally to UNC13B through shared mechanisms) involves TDP-43-dependent cryptic splicing in ALS, FTD, and Alzheimer's disease 456.