Purified anti-human CD307d (FcRL4)

FcRL4 (Fc receptor-like 4) is a 57 kD single pass type I transmembraneprotein that exhibits 4 Ig like C2 domains. Also known as ITRA1, IGFP2, and FcRH4, FcRL4 is predominately found on a subset of memory B cells. Activation of FcRL4 contributes to B cell receptor inhibition through activation of the tyrosine kinases SHP-1 and 2. FcRL4's nascent loci is 1q23.1; however,breakpoint mutations are associated with multiple myeloma and non-Hodgkins lymphoma. Increased FcRL4 expression on memory B cells has also been observed in HIV viremic patients. FcRL4 predominately binds aggregated IgA, binds weakly with IgG3 and IgG4, and does not bind IgG1 and IgG2.