Overall antibody response Generally, PC-BSA-IgM titers were affected by housing (F(1.52) = 4.2), P < 0.05), sampling day (F(6.307) = 124.0, P < 0.001), their interaction (F(6.307) = 5.1, P < 0.001), infection (F(1.52) = 13.1, P < 0.001), and the housing × infection × sampling day interaction (F(6.307) = 2.8, P < 0.05) (Figure 1E). This evidence concerns the gene CD40LG and infection.