MMP1 and Arterial thrombosis: Moreover, MPN patients carrying the MMP-1 rs19799750 1G2G genotype (vs 2G2G) tended to have an increased risk of arterial thrombosis (p = 0.059), while the MMP-3 rs3025058 6A6A genotype (compared to 5A5A) showed a tendency towards decreased arterial thrombosis (p = 0.058) (Table 2).