In other studies, we also observed a lower rate of HF-related death in HF patients who carried the 2 G allele of the −1607 1 G/2 G polymorphism in the MMP-1 gene18, the TT genotype of the −790 G > T polymorphism in the MMP-2 gene19, or the 6 A allele of the −1171 5 A/6 A polymorphism in the MMP-3 gene18 than patients with other genotypes. The gene discussed is MMP1; the disease is hydrops fetalis.