So this involves not T lymphocytes but B lymphocytes or B cells. And we also have different types of B cells. We have plasma B cells and we have memory B cells and we'll discuss their unique individual function in the next several lectures. So these cells are responsible for producing a type of biological immune or defense molecule known as the antibody. So antibodies are essentially these proteins that circulate throughout our blood and they can attach and recognize the antigens of bacterial cells and other pathogens. And by binding to these antigens, what the antibodies do is they help our immune system initiate these defense mechanisms that ultimately kill off those harmful pathogens.