IL12A and infection: Croix ancestry that were artificially infected with H. contortus at 120–150 days of age and compared to lambs of a composite (50% Dorset, 25% Rambouillet, 25% Finnish Landrace) wool-sheep line had lower expression of IL12A (i.e., the p35 subunit of IL-12 and IL-23) in abomasal tissue and lower expression of IFNγ in lymph nodes at 3 days after infection (MacKinnon et al., 2009).