MMP9 and stroke disorder: Il1b, Mmp9, and Apoe for stroke pathogenesis; Aif1 (Iba1) microglial; Sall1 microglia and Cd44 in infiltrated myeloid cells; CD11c (Itgax) in DC, NKs, and monocytes/macrophages; Flt3 in DC for aged stroke brain