Well, what happens next is for any type of mechanism, for any type of defensive mechanism to actually take place, our B cell must react, must interact with our T cell, our T lymphocyte. So a special type of T lymphocyte known as the helper T cell that contains the complementary T cell receptor, complementary to this particular section of our antigen and MHC class two complex. And also the helper T cell must have the CD four glycoprotein to actually be able to bind, interact with the section of our B cell. So here we have the B lymphocyte that essentially contains the antigen bound to the MHC class two complex. So if we have a nearby helper T cell that contains not only the complementary T cell receptor and this CD four, but also this CD four glycoprotein, only then can this binding process takes place. And once this binding process takes place between the B lymphocyte and our helper T cell, now we begin to initiate different types of defensive responses.