MMP9 and stroke disorder: Finally, several studies and meta-analyses have described other possible biomarkers for stroke diagnosis, including matrix metalloproteinase 9 (MMP-9) (83, 84), Brain natriuretic peptide (BNP) (85), N-methyl-D-aspartate receptor proteins (86) and apolipoproteins (87, 88), which may also help to discriminate between atheroembolic stroke and other main etiologies (89).