The infection with Salmonella upregulated statistically significantly TLR4 mRNA expression in all Salmonella-challenged minipigs (LT2, RP36+LT2, RP37+LT2, and LA+LT2) compared to non-challenged ones (GF, RP36, RP37, and LA) (Figure 4A). The gene discussed is TLR4; the disease is infection.