PSAT1 and cancer: Previous studies have demonstrated that certain types of cancer show increased de novo synthesis of serine, which is formed from the glycolytic intermediate 3-phosphoglycerate (3-PG) through a series of reactions mediated by phosphoglycerate dehydrogenase (PHGDH), phosphoserine aminotransferase 1 (PSAT1), and phosphoserine phosphatase (PSPH).