EGR1 and cardiac hypertrophy: While NAB1 does not impede DNA binding or nuclear localization, it directly binds to the repression domain of transcription factors such as EGR1, EGR2, and EGR3 to repress DNA promoter activity.[9, 10] Mutations affecting this domain led to decreased repression of EGR2 through NAB1.[11] In cardiac physiology, NAB1 exhibits upregulation in conditions of cardiac hypertrophy and heart failure.