Phosphorylcholine chloride calcium salt tetrahydrate (Phosphocholine chloride calcium salt tet) is a small haptenic molecule, is found in a wide variety of organisms. Human hepatic tumors undergo an elevation in the concentration of phosphorylcholine as the principal metabolic change is observed (PMID: 11076016 ). Phosphorylcholine chloride calcium salt tetrahydrate is the precursor metabolite of choline in the glycine, serine and threonine metabolism pathways (KEGG, map00260) and in intermediate between choline and cytidine-diphosphate choline in the glycerophospholipid metabolism pathway (KEGG, map00564).