Grancalcin (GCA) is a member of the penta EF hand subfamily which includes sorcin, calpain and ALG2. Grancalcin is highly expressed bone marrow and also can detected in neutrophils and macrophages. Grancalcin interacts with L-plastin which known to have actin bundling activity. It indicates that Grancalcin may play an important role in the adhesion of neutrophils to fibronectin. Furthermore, Grancalcin localization is dependent upon calcium and magnesium. It associates with both the granule and membrane fractions, which suggested a role for grancalcin in granule-membrane fusion and degranulation.