Macrophages stimulated by cellular interleukin-12, tumor necrosis factor-α, interferon-γ, bacterial lipopolysaccharide, Toll-like receptor agents, and pathogen-associated molecular patterns can be polarized to M1-type and play an important role in mediating T helper cell 1-type immune response and anti-pathogen infection 46, 47. This evidence concerns the gene TNF and infection.