In patients with diabetic foot ulcers, MMP-2/-9 are linked to the healing process of dermal ulcers, and increased expression of these MMPs is correlated with ulcer chronicity; particularly, MMP-2 is considered the biomarker of connective tissue remodeling, and MMP-9 is the biomarker of inflammatory cell infiltration [94]. The gene discussed is MMP9; the disease is diabetic foot.