Enolase 1 (ENO1), also known as alpha‑enolase, is a glycolytic enzyme that catalyzes the conversion of 2‑phosphoglycerate to phosphoenolpyruvate. It is ubiquitously expressed and accounts for the majority of cytosolic enolase activity. Beyond its metabolic role, ENO1 is a multifunctional “moonlighting” protein: on the cell surface it acts as a plasminogen receptor promoting extracellular matrix degradation and tumor invasion, while a nuclear isoform (MBP‑1) binds the c‑MYC promoter and regulates transcription. Overexpression of ENO1 has been linked to cancer progression, autoimmune diseases, and neurodegeneration, making it both a biomarker and a potential therapeutic target.