Humoral immunity and cellular immunity are two immune mechanisms in the human body, both of which need to be produced in response to antigenic stimulation. Humoral immunity is the production of effector B cells and memory cells by a type of B cell in the body after stimulation by an antigen, which in turn produces antibodies and generates an immune response to the corresponding antigen, or in short, the production of antibodies against the antigen after stimulation by a pathogen, whose main target is extracellular pathogens and toxins, with the result that the disease is healed. In contrast, cellular immunity is the direct formation of memory T cells and effector T cells by human T cells after receiving antigenic stimulation, which in turn produce antibodies. The difference is that such antibodies require specific binding to cells in order to exert an immune response, and therefore target intracellular antigens and toxins, and even cancerous cells. Cellular immunity plays an important role in infections and tumors in the body, and is also involved in delayed allergic reactions and autoimmune diseases in the body. In addition, cellular immunity has a regulatory role on humoral immunity.