As presented in Figure 1, we can observe that the CTSG levels are significantly higher in the supernatants of MAP-infected CD14+-MDMs obtained from cows carrying the C allele (1.85 ± 0.11 ng/mL) after 2 h of infection than in infected CD14+-MDMs from cows with the AA genotype (1.68 ± 0.06 ng/mL) (p = 0.008). This evidence concerns the gene CTSG and infection.