MMP1 and small artery occlusion: An analysis of MMP-1 (-1607 1G/2G) and MMP-3 (-1171 5A/6A) polymorphisms in subtypes of IS revealed higher frequency of the 5A/6A+5A/5A genotypes and 5A allele in the overall investigated population with IS, whereas MMP-1 1G/2G and 2G/2G genotypes were associated with higher susceptibility for small-artery occlusion subtype and MMP-3 5A/6A+5A/5A genotypes enhanced the risk of large-artery atherosclerosis as well the first occurrence as recurrence, but not small-artery occlusion and cardioembolism [154,155].