SLAM family member 7/CRACC is a type I transmembrane glycoprotein in the SLAM subgroup of the CD2 family. SLAM receptors triggered by homo- or heterotypic cell-cell interactions are modulating the activation and differentiation of a wide variety of immune cells and thus are involved in the regulation and interconnection of both innate and adaptive immune response. Activities are controlled by presence or absence of small cytoplasmic adapter proteins, SH2D1A/SAP and/or SH2D1B/EAT-2. Mature mouse CRACC consists of a 202 amino acid extracellular domain (ECD) with one Ig-like V-set domain and one Ig-like C2-set domain, a 21 aa transmembrane segment, and an 88 aa cytoplasmic domain with two immunoreceptor tyrosine-based switch motifs ITSMs. CRACC is expressed on the surface of NK cells, CD8+ T cells, activated B cells, and mature dendritic cells. It interacts homophilically to induce NK, CTL, and B cell activation.