NEUROD4 is a basic helix-loop-helix (bHLH) transcription factor that functions as a transcriptional activator mediating neuronal differentiation and cell fate specification 1. As a direct target of proneural factors like ASCL1 and NEUROG2, NEUROD4 is required for efficient astrocyte-to-neuron and fibroblast-to-neuron reprogramming, working synergistically with SOX4 to upregulate neuronal genes 23. In the developing nervous system, NEUROD4 expression is directly repressed by the transcription factor Brn3a in embryonic sensory neurons 4. Beyond neuronal development, NEUROD4 has been identified as a component of ferroptosis-related gene networks implicated in Parkinson's disease pathogenesis 5, and as a DNA methylation-regulated gene associated with lung adenocarcinoma prognosis 6. NEUROD4 serves as a neuronal differentiation marker in dopaminergic neuron cultures and cellular toxicity screening models 7. Genetic screening has not identified NEUROD4 mutations as significant contributors to monogenic diabetes in Japanese populations 1, distinguishing it functionally from related bHLH factor NeuroD1/BETA2.