This past week, I delved into the arena of Matrix Metalloproteinases and their role in disease and Pulmonary Hypertension. One of the first papers that I read with regards to this is by S.S. Pullamsetti et al. entitled “Matrix metalloproteinases and their inhibitors in pulmonary hypertension”. My review and summary of this paper is below. Abbreviations: ECs = Endothelial Cells SMCs = Smooth Muscle Cells ECM = Extracellular Matrix PAH = Pulmonary Arterial Hypertension MMPs = Matrix Metalloproteinases TIMPs = Tissue Inhibitors of Matrix Metalloproteinases In PAH, complex remodeling is observed in the pulmonary vasculature that involves all components of the blood vessel.