However, other murine studies deploying global deficiency or macrophage-restricted overexpression of MMP-9 within the LAD ligation-induced MI model have associated MMP-9 expression with reduced cardiac fibrosis post-MI, alongside diminished macrophage accumulation and left ventricular enlargement, but enhanced neovascularization42,43. The gene discussed is MMP9; the disease is myocardial infarction.