Macrophages infected with the recombinant strain overexpressing Rv1899c (MS_Rv1899c) produce significantly lower levels of the pro-inflammatory cytokines IL12B, IL-1β, IL-6 and higher levels of anti-inflammatory cytokine IL-10 (Figure 6A–D) compared with those infected with the vector control strain (MS_Vec) after 24 h of infection. Here, IL6 is linked to infection.