Once these pathogens enter the mammary gland and detected by epithelial cells together with resident macrophages, the cells will release inflammatory cytokines such as TNF-α (tumor necrosis factor–alpha), IL-1β (interleukin-1 beta), humoral components (alexin, antibodies, antimicrobial peptides) are also participate in the process, and then, more leukocytes (neutrophils and lymphocytes) will be attracted under the chemotaxis, and more cytokines be synthesized and secreted; in the end, bovine mastitis is induced till the mastitis pathogens are eliminated (5). Here, TNF is linked to mastitis.