IL6 and infection: These findings suggest that, regardless of the expression of Btp proteins, the immune response mounted in the lung during the first stages of infection is not enough to reduce the pulmonary load of Brucella. In line with these findings, a recent study has also suggested that the pulmonary inflammatory response is irrelevant for the early control of B. melitensis after intranasal infection, as pulmonary CFU counts did not differ between wild-type mice and those deficient for IL-1R, IL-6, TNF-α, or CCR2 (29).