Phosphogluconate dehydrogenase (PGD) is a cytosolic enzyme that catalyzes the oxidative decarboxylation of 6-phosphogluconate to ribulose 5-phosphate and CO2, with concurrent reduction of NADP to NADPH, representing a critical step in the oxidative branch of the pentose-phosphate pathway. This metabolic function is essential for generating NADPH, a reducing agent required for biosynthetic reactions and cellular redox homeostasis. Recent evidence reveals PGD's broader pathophysiological significance. PGD expression is elevated in polycystic ovary syndrome (PCOS) and endometrial cancer (EC) tissues, where it functions as a shared risk factor linking these conditions 1. Mechanistically, PGD influences cell proliferation and migration through modulation of glycometabolism and single-carbon metabolism within the broader carbon metabolism pathway 1. Suppression of PGD expression impedes glycometabolic flux in endometrial cancer cells, suggesting its role in disease progression 1. These findings indicate PGD operates at the intersection of metabolic regulation and cellular proliferation. Beyond its canonical role in pentose-phosphate metabolism, PGD represents a potential therapeutic target for conditions characterized by aberrant glucose metabolism and uncontrolled cell proliferation, particularly in hormone-sensitive malignancies and metabolic disorders. Further investigation into PGD's regulation and its interactions with glycometabolic signaling pathways may provide insights into PCOS pathogenesis and endometrial cancer biology.