RBFOX3 is an RNA-binding protein that functions as a pre-mRNA alternative splicing regulator in the nervous system 123. The protein localizes to the nucleoplasm and cytoplasm, where it regulates alternative splicing of RBFOX2 to enhance the production of mRNA species targeted for nonsense-mediated decay 1. RBFOX3 serves as a neuronal marker used to identify and characterize neuronal populations and their dynamic transcriptome profiles 45. Recent large-scale genomic analysis identified RBFOX3 as associated with epilepsy susceptibility, representing a novel disease-gene relationship discovered through rare variant burden analysis in the 100,000 Genomes Project 6. The gene plays roles in nervous system development and maintains neuronal integrity across multiple pathological contexts, including traumatic brain injury, chr17 pain with comorbid anxiety, and neurodegenerative conditions 378. RBFOX3's expression patterns help distinguish neuronal subpopulations with distinct functional states, particularly in pancreatic islet gamma cells 4. These findings establish RBFOX3 as an important regulator of neuronal function with emerging clinical relevance to neurological and neuropsychiatric disorders.