In summary, increased uncarboxylated GRP (ucGRP) expression has been found at sites of osteogenic deposits, like in calcified aortic valves or PXE skin lesions, while carboxylated GRP (cGRP) was shown to inhibit VC to the same extent as cMGP [68,82]. The gene discussed is GRP; the disease is pseudoxanthoma elasticum (inherited or acquired).