MMP9 and tuberculosis: It has been reported that key transcriptional regulators of MMP expression in TB are NF‐κB and STAT3.30, 97, 98 TIMP‐1 lacks an NF‐κB promoter binding site, and so, NF‐kB signalling may regulate the MMP/TIMP expression.55 Recently, Miao and colleagues reported that IL‐12 significantly increases the mRNA and protein level expressions of MMP‐1, MMP‐3 and MMP‐13, and downregulates MMP‐2 and MMP‐9 in the human periodontal ligament fibroblasts.86 NF‐κB signalling was involved in this IL‐12‐mediated regulation of MMPs.