ITGAM transcript, CD11b primary protein domains, and CR3 protein. (A) ITGAM genomic organization showing relative positions of common polymorphisms (R77H, M441T, A858V) and novel rare variants (F941V, G1145S). (B) Primary protein domains of CD11b and the relative location of the missense variants. The β-propellor domain is shown in dark blue; the ligand-binding I-domain is shown in green; light blue represents the other extracellular domains; the transmembrane domain is shown in yellow, and the short cytoplasmic tail is represented in orange. (C) A cartoon diagram of the CR3 protein (Protein domain ratios = extracellular/transmembrane/cytoplasmic = 1:6:6). The same colors as (B) are used to represent the various domains; CD18 is shown in light purple. Asterisks are used to indicate the position of missense variants used in the functional studies: M441T, A858V, F941V, and G1145S.