TNF and Nematoda infectious disease: Furthermore, at 3 weeks p.i., only IFNγ and tumor necrosis factor-alpha (TNFα) were produced by CD8+ T cells in the lamina propria, with a highly significant increase in the proportion of CD8+ cells producing IFNγ associated with nematode infection (i.e., the mice dosed with nematode eggs) across host environments (S6D Fig; S3 Table; P < 0.0001).