Pyrophosphate inhibits mineralization, and tissue non-specific alkaline phosphatase (TNSALP) increases phosphate concentration by cleaving pyrophosphate, which is important for the regulation of mineralization in bone. Moreover, PC-1 (plasma cell membrane glycoprotein-1) on matrix vesicle and osteoblast plasma membrane, as well as ANK (ankylosis) on osteoblast plasma membrane induce extracellular pyrophosphate. The pyrophosphate production by PC-1 and ANK and TNSALP, as well as some mineralization-inhibiting factors,(for example osteopontin) induced by these molecules, is considered to maintain the normal process of mineralization. The abnormality of these molecules causes various mineralization disorders.