CD79a is a 47kD type I integral membrane protein, also known as mb-1 or Iga. It is a member of the Ig superfamily and disulphide-associated with CD79b (B29). The interaction of CD79a/CD79b heterodimer with B cell suface Ig forms B cell antigen complex. CD79a is expressed in B cells from early pre-B to plasma cell stage. It has been shown that CD79a is also weakly expressed in some precursors of T- and myeloid cells.CD79 mediates the transport of IgM to B cell surface and transduces signals initiated by BCR aggregation