Tissue-nonspecific alkaline phosphatase: a promising target for pseudoxanthoma elasticum therapy

In mammals, biominerals consist of calcium and phosphate which form hydroxyapatite. Complex molecular and cellular mechanisms have evolved permitting crystallization of calcium and phosphate (i.e., forming hydroxyapatite) only at specific sites of the body. Pyrophosphate (PPi) is a central factor in the prevention of pathological calcium-phosphate precipitation in soft peripheral tissues [for a recent review see (1)].