Nrf2 (nuclear factor erythroid 2-related factor 2) is a key transcription factor that regulates cellular antioxidant stress response capacity by activating antioxidant response elements (AREs) to control gene expression, thus maintaining redox balance and metabolic homeostasis. Belonging to the Cap 'n' Collar (CNC) family, it shares a basic leucine zipper (bZIP) domain with Nrf1, Nrf3, and p45 NFE2, forming heterodimers that bind DNA. When inactive, Nrf2 forms a complex with the Keap1 protein in the cytoplasm, but upon oxidative stress, it translocates into the nucleus to activate gene expression. Nrf2 expression is tissue-specific and crucial for antioxidant defense in organs such as the heart, liver, and kidneys. Mutations or dysregulation of Nrf2 are associated with cancer, neurodegenerative diseases, and chronic inflammatory conditions, making it an important drug target.