MMP9 and infection: To validate the microarray gene expression profile of BMM during infection by Mtb , we performed qRT-PCR for selected genes encoding mediators of host immunity, including pro-inflammatory cytokines (IL-1β and IL-6), chemokines (CXCL9 and CCL8), cell adhesion and tissue remodeling (MMP9 and CD209F) and host lipid metabolism genes (Figure 3 and Table 2).