MMP12 and Hepatic fibrosis: A CD11bhi/F4/80infLY6Clow macrophage subpopulation was identified during the resolution of liver fibrosis; these special cells do not produce fibrogenic and/or inflammatory factors, but they continue to secrete MMPs, including MMP9 and MMP12 [59,74,89], and they upregulate CX3CR1.