“…In chicken, TLR4 has been identified in leukocytes and other tissues, including the liver, kidneys, lungs, fallopian tubes, small intestine, colon, and spleen. Moreover, TLR4 expression was found in leukocytes and heterophils from various chicken breeds [ 18 , 19 ]. Toll-like receptor 4 responds to LPS in mammals and birds by activating immune cells, such as monocytes, macrophages, and B cells, that combat infections [ 20 , 21 ].…”