NAB1 (NGFI-A binding protein 1) is a transcriptional corepressor that functions as a negative regulator of zinc finger transcription factors, particularly EGR1 and EGR2 1. NAB1 executes its repressor function through protein-protein interactions, where it binds to an inhibitory domain on EGR1 and brings corepressor activity to target genes 1. The protein is ubiquitously expressed across human cell lines and can completely block EGR1-mediated transcription when overexpressed 1. NAB1 displays position-independent transcriptional repression activity and functions as a docking site for corepressor machinery 1. NAB1 plays important roles in immune regulation and developmental processes. It is rapidly upregulated by anti-inflammatory lipoxin A4 analogs in human neutrophils through G protein-coupled receptor signaling 2, linking it to inflammation resolution. In the peripheral nervous system, NAB1 partners with EGR2/Krox-20 to regulate myelination, and dysregulation of this axis contributes to Charcot-Marie-Tooth disease and related neuropathies 3. NAB1 genetic variants are associated with multiple autoimmune diseases, including narcolepsy type 1 4 and Sjögren's disease 5, suggesting roles in T cell autoimmunity and immune cell function. Additionally, NAB1-derived circular RNAs and novel protein isoforms modulate cardiac fibrosis and inflammation in atrial fibrillation 6, indicating broader physiological roles beyond transcriptional repression of EGR factors.