Human bone-forming osteoblasts are an excellent model to investigate the mu
ltiple functions of inorganic polyphosphates (polyP) for the following reas
ons: 1) they contain relatively high amounts of polyP and polyP-dependent e
nzymes; 2) they allow the study of both general and specific functions of t
hese polymers, and 3) medically relevant results can be expected from these
studies.