MMP8 and periodontitis: (Lauhio et al., 2016) Host modulation therapy through the administration of sub‐antimicrobial doxycycline reduces systemic collagenolytic and pro‐inflammatory (hsCRP, TNF‐α, MMP‐9) biomarkers including MMP‐8 and this therapy have been demonstrated to be an effective adjunct to nonsurgical periodontal treatment in the management of periodontitis.