Several enzymes involved in de novo serine/glycine biosynthetic pathway including phosphoglycerate dehydrogenase (PHGDH), phosphoserine aminotransferase 1 (PSAT1) and serine hydroxymethyltransferase (SHMT), are highly up-regulated in various cancers and associated with poor-prognosis of cancer patients [134]. Here, PHGDH is linked to cancer.