HK1 and rheumatoid arthritis: For example, deficiency of the glycolytic enzyme 6‐phosphofructo‐2‐kinase/fructose‐2,6‐bisphosphatase isoenzyme 3 (PFKFB3) in RA impairs redox balance, autophagy and decreases glycolysis, thus decreases ATP generation in naïve T cells, which instead exhibit increased activity of the pentose phosphate pathway (PPP) and NADPH production.61