CD79a is the B-cell lineage marker in neoplasm required with CD79b to initiate the signal transduction cascade. The process is activated by binding B-cell antigen receptor complex (BCR) to the antigen. The CD79A protein gene, besides differentiation of pro- and pre-B-cells Stimulates SYK autophosphorylation. Proteins CD79a and CD79b collectively form dimer incorporated with the membrane-bound to immunoglobulin in the B-cells. It also forms B-cell antigen receptor BCR and occurs in the same way to the link of CD3 with the T-cell receptor and facilitates the cell activity in response on the surface. Agammaglobulinemia is a condition that arises due to mutations affecting the gene.