– Signal-regulatory protein beta-2(SIRP-beta-2), is a monomeric single pass type I membrane glycoprotein, belongs to the SIRP/SHPS (CD172) family of the immunoglobulin (Ig) superfamily. The SIRP family are paired receptors that have similar extracellular domains but differing C-terminal domains and functions. A positively charged residue within the transmembrane domain, in analogy to SIRP-beta-1, is implicated to mediate interaction with the adaptor DAP12 protein, which contains immunoreceptor tyrosine-based activation motifs (ITAMs). Proteins in the SIRP family are typically expressed in immune cells, especially in the myeloid lineages. Based on expression patterns, SIRPs are thought to have roles in immune regulation. SIRP family members role in innate immunity and host defense has potential significance as a therapeutic target in cancer and inflammation. There are currently no known mouse or rat homologs for this protein.