MMP12 and ischemic stroke: In addition, typical genes of neurodegeneration-associated microglial subgroups (i.e., Lgals3, Lilrb4, Lpl, Spp1, and Fth1) (8) and MMP12 (matrix metalloproteinases 12) known to cause damage to the BBB upon ischemic stroke (149) were also upregulated (Figure 4).