In the first reported Mtb infections of Nod2-deficient animals (aerosol infections with 35 CFU of strain 1254 or 1,500 CFU of H37Rv), the burden of Mtb in the lungs of Nod2-KO C57BL/6 mice was indistinguishable from WT mice up to 8 weeks post aerosol infection, with no obvious histopathological differences and only a small increase in serum IL-12p40 in the knockout at earlier time points [18]. Here, NOD2 is linked to infection.