CD79b molecule, immunoglobulin-associated beta, also known as CD79B (Cluster of Differentiation 79B), is a human gene. It is associated with agammaglobulinemia-6. The B lymphocyte antigen receptor is a multimeric complex that includes the antigen-specific component, surface immunoglobulin (Ig). Surface Ig non-covalently associates with two other proteins, Ig-alpha and Ig-beta, which are necessary for expression and function of the B-cell antigen receptor. This gene encodes the Ig-beta protein of the B-cell antigen component. Alternatively spliced transcript variants encoding different isoforms have been described.