Calgranulin B: A 13.2-kDa member of the S-100 family of calcium-binding proteins that can form homo- or heterocomplexes with CALGRANULIN A and a variety of other proteins. The calgranulin A/B heterodimer is known as LEUKOCYTE L1 ANTIGEN COMPLEX. Calgranulin B is expressed at high concentrations in GRANULOCYTES during early monocyte differentiation, and serum calgranulin B levels are elevated in many inflammatory disorders such as CYSTIC FIBROSIS.Calgranulin A: A 10.8-kDa member of the S-100 family of calcium-binding proteins that can form homo- or heterocomplexes with CALGRANULIN B and a variety of other proteins. The calgranulin A/B heterodimer is known as LEUKOCYTE L1 ANTIGEN COMPLEX. Calgranulin A is found in many cell types including GRANULOCYTES; KERATINOCYTES; and myelomonocytes, and has been shown to act as a chemotactic substance for NEUTROPHILS. Because it is present in acute inflammation but absent in chronic inflammation, it is a useful biological marker for a number of pathological conditions.S100 Proteins: A family of highly acidic calcium-binding proteins found in large concentration in the brain and believed to be glial in origin. They are also found in other organs in the body. They have in common the EF-hand motif (EF HAND MOTIFS) found on a number of calcium binding proteins. The name of this family derives from the property of being soluble in a 100% saturated ammonium sulfate solution.Leukocyte L1 Antigen Complex: A member of the S-100 protein family that is present at high levels in the blood and interstitial fluid in several infectious, inflammatory, and malignant disorders, including rheumatoid arthritis, inflammatory bowel disease, and cystic fibrosis. It is a complex of a light chain (CALGRANULIN A) and a heavy chain (CALGRANULIN B). L1 binds calcium through an EF-hand motif, and has been shown to possess antimicrobial activity.Calcium-Binding Proteins: Proteins to which calcium ions are bound. They can act as transport proteins, regulator proteins, or activator proteins. They typically contain EF HAND MOTIFS.