Now what the role of the AlphaBeta T lymphocyte is is to actually bind to these antigen MHC complexes once the antigen presenting cell actually engulfs that antigen and places it onto that MHC in the first place. Now, on top of having that T cell receptor that consists of an alpha and a beta subunit these T lymphocytes also contain glycoproteins that are necessary to actually bind to the antigen presenting cells. Now, we have two different types of glycoproteins. We have CD four glycoproteins and we have CD eight glycoproteins. And the difference between these two different glycoproteins is their ability to bind to different types of major histocompatibility complexes. So let's begin with the CD four AlphaBeta T cell.