MMP12 and ischemic stroke: Although various brain cells (neurons, oligodendrocytes, and microglia) express MMP-12 in the brain following an ischemic stroke, the primary source of MMP-12 is the monocytes/macrophages that have infiltrated into the ischemic brain (Wu et al., 2000; Svedin et al., 2009; Chelluboina et al., 2015b).