PHGDH and colorectal carcinoma: Proteomic studies have shown upregulations of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and malate dehydrogenase (MDH) but down-regulations of phosphoenolpyruvate carboxykinase (PEPCK), UDP-glucose pyrophosphorylase 2 (UGP2) and aconitate hydratase in CRC tissues compared to these in adjacent normal mucosa indicating the CRC-associated alterations in multiple metabolic pathways such as glycolysis/gluconeogenesis, glucuronate pathway and tricarboxylic acid cycle17, 18, 19.