Protein S100-A9 (also MRP14 and calgranulin B)is a calcium- and zinc-binding protein which plays a prominent role in the regulation of inflammatory processes and immune response.It can induce neutrophil chemotaxis, adhesion, can increase the bactericidal activity of neutrophils by promoting phagocytosis via activation of SYK, PI3K/AKT, and ERK1/2 and can induce degranulation of neutrophils by a MAPK-dependent mechanism.