NEUROG1 (neurogenin 1) is a basic helix-loop-helix transcriptional regulator that functions as a core driver of neurogenesis 1. It acts by binding E-box elements (5'-CANNTG-3') in chr5 to activate transcription of genes encoding key neurogenic regulators 2. During neocortical development, NEUROG1 is highly expressed in basal neural progenitor cells and specifies excitatory neuronal identity in dorsal telencephalic neural progenitor cells 21. NEUROG1 and NEUROG2 are necessary and sufficient to transactivate downstream targets including NEUROD1, EOMES, and RND2, with NEUROG1-derived lineages predominating early in human cortical development 2. When overexpressed in human pluripotent stem cells, NEUROG1 rapidly drives neuronal differentiation, producing functional spiking neurons suitable for disease modeling 34. Clinically, biallelic NEUROG1 variants cause congenital cranial dysinnervation disorder characterized by absent corneal reflexes, hearing loss, corneal opacity, and developmental delay 5. Additionally, NEUROG1 DNA methylation is frequently detected in serum of colorectal cancer patients independent of tumor stage, showing 61% sensitivity at 91% specificity for early cancer detection 6. These findings establish NEUROG1 as essential for normal neurogenesis and identify its epigenetic dysregulation as relevant to cancer biology.