In ruminants, HP and SAA are considered dominant APPs that increase throughout infections, inflammatory conditions, surgical trauma, and stresses (Heegaard et al., 2000; Petersson-Wolfe, Mullarky & Jones, 2010; El-Deeb, Elmoslemany & Salem, 2017; El-Deeb et al., 2020a). This evidence concerns the gene HP and infection.