ENO1 and rheumatoid arthritis: More recently, we and others have shown that the auto-antibody repertoire in early untreated RA is directed against several categories of antigens, notably some enzymes of the glycolytic pathway such as aldolase, phosphoglycerate-kinase 1, glucose-6-phosphate isomerase (G6PI) and ENO1, and chaperone molecules including calreticulin, HSP-60 and BiP6.