So recall that antigen presenting cells are cells such as macrophages, dendritic cells and belymphocytes that engulf antigens and then present those antigens to the T lymphocytes by using their major histocompatibility protein complexes found on the membrane. And we have these two different classes of these major histocompatibility complexes. The class one are responsible for differentiating between infected cells and healthy cells. And class two is used for communicating between different types of white blood cells. So AlphaBeta T cells can only interact with these antigen presenting cells. Now, what about the other category of T cells known as the gamma delta T cells?