In the comparisons of cows with diffuse vs. focal lesions, AS events were associated with the upregulation of the complement C2 and C4A genes involved in complement activation (GO:006956 and GO:006958), humoral immune response mediated by circulating immunoglobulins (Ig) (GO:0002455), Igs-mediated immune response (GO:00160664), and B-cell-mediated immunity (GO:0019724), and with the pathogenesis of several human diseases such as Pertussis (bta:05133), an acute respiratory infectious disease caused by Bordetella Pertussis, and Staphylococcus aureus infection (bta:05150). Here, C2 is linked to pertussis.