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.