PGM2 (phosphoglucomutase 2) is a cytosolic enzyme that catalyzes the reversible conversion of alpha-D-glucose 1-phosphate to alpha-D-glucose 6-phosphate via the intermediate alpha-D-glucose 1,6-bisphosphate 1. PGM2 also converts nucleoside breakdown products ribose-1-phosphate and deoxyribose-1-phosphate to corresponding 5-phosphopentoses, participating in purine ribonucleoside salvage 1. Unlike PGM1, PGM2 is uniquely inhibited by ribose monophosphates and displays phosphoribomutase activity, reflecting its specialized role in nucleotide metabolism 2. PGM2 is essential for galactose utilization; mutations causing PGM2 truncation severely impair galactose metabolism in yeast, demonstrating its critical function in carbohydrate metabolism 3. Clinically, PGM2 upregulation correlates with poor prognosis in lung adenocarcinoma, associating with advanced TNM stage, high-grade malignancy, unfavorable overall survival (HR=1.54), disease-specific survival (HR=1.77), and reduced immune cell infiltration 4. PGM2 variants are also associated with childhood-onset asthma through genome-wide sequencing analysis 5. Additionally, environmental exposures affecting PGM2 expression may disrupt hepatic metabolic homeostasis and glucose metabolism 6. These findings establish PGM2 as both a fundamental metabolic enzyme and an emerging biomarker for disease prognosis.