GGCX and pseudoxanthoma elasticum (inherited or acquired): While rodent model data appear negative, the existence of a PXE-like disorder with coagulation factor deficiency–caused by GGCX (Gamma-Glutamyl Carboxylase) mutations–where VK-dependent carboxylation is (nearly) abolished suggests an important role for VK in mineralization homeostasis (Vanakker et al., 2010).