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. CD44, also known as CD44 antigen, ECMRIII (Extracellular matrix receptor III), HCAM (Homing cell adhesion molecule), Pgp-1 (phagocytic glycoprotein-1), HUTCH-1, etc., is cell surface adhesion receptor and transmembrane glycoprotein in humans encoded by the CD44 gene on the chromosome 11p13. It is a ubiquitous glycoprotein produced throughout the body with a molecular weight of about 85-200 kDa. CD44 contains certain primary domains including the ectodomain, the transmembrane and intracellular domain. It is probably the most well-characterized receptor for hyaluronic acid (HA) and has been reported to be involved in adhesive cell-cell and cell-matrix interactions, cell migration and cell homing. CD44 is also a widely distributed transmembrane adhesion molecule with high expression in cancers.