Protein C(PROC), also called PC, is a zymogenic (inactive) protein, the activated form of which plays an important role in regulating blood clotting, inflammation, cell death and maintaining the permeability of blood vessel walls in humans and other animals. The PROC gene is mapped on 2q14.3. The PROC gene contains 8 exons and spans about 11 kb by Foster et al. The conversion of protein C to a protease with anticoagulant function by thrombin requires as a cofactor thrombomodulin, an endothelial cell membrane protein. Riewald et al. demonstrated that activated protein C uses the endothelial cell protein C receptor as a coreceptor for cleavage of protease-activated receptor-1 on endothelial cells. Faust et al. demonstrated that the endothelial pathways required for protein C activation are impaired in severe meningococcal sepsis. They stated that improvement in the outcome of children with meningococcal sepsis who were treated with unactivated protein C concentrates had been described in case reports and in 1 uncontrolled series.