CD45 called CD45RB is a member of the protein tyrosine phosphatase (PTP) family. The PTP proteins are signalling molecules that are involved in a variety of cellular processes including cell growth, differentiation, mitosis and oncogenesis. CD45 is an essential regulator of T- and B-cell antigen receptor signalling. CD45 has various isoforms generated by different splicing of exons. Clone C363-16A recognises CD45RB, generated by exon 5 splicing. This 220kDa glycoprotein is expressed on peripheral B-cells, na