CD20 or B-lymphocyte antigen CD20 is a non-glycosylated phosphoprotein which is expressed on the surface of mature naive B cells. In humans, CD20 is encoded by the gene, membrane spanning 4-domains A1 (MS4A1). Diseases associated with this gene include immunodeficiency and common variable. The related pathways among CD20 are B cell development pathways, together with hematopoietic stem cell differentiation pathways and lineage-specific markers. CD20 is membrane-embedded surface molecule with about 33-37 kDa and plays a key role in the development and differentiation of B-cells into plasma cells. It is also important for the regulation of intracellular calcium involved in transmembrane calcium influx. Measuring CD20 antigen on blood cells may aid to diagnose cancer so that it is considered as a type of tumor marker. CD3 (Cluster of differentiation 3), originally known as T3, is one of the first groups of human T lymphocyte surface antigens recognized by monoclonal antibodies. It has been reported that antibodies against CD3 could either stimulate T cells to divide or inhibit the progress of effector functions according to the conditions used. It plays an important role in T cell and the CD3 T-cell co-receptor helps to activate the cytotoxic T-Cell and T helper cells. The CD3 molecule is composed of a protein complex and consists of four distinct chains. The complex of mammals contains a CD3γ chain, a CD3δ chain, and two CD3ε chains. All these chains associate with T-cell receptor and the ζ-chain to generate an activation signal in T lymphocytes.