MMP activity contributes to chronic wound formation not only through degradation of the extracellular matrix, but also through increased liberation of inflammatory cytokines such as TNFα and IL-1β, so the activity of miR-491-5p in lowering pressure ulcer risk may involve both lowering inflammatory signaling and decreasing ECM breakdown and the regulation of MMP9 activity [134,135]. Here, MMP9 is linked to decubitus ulcer.