MMP9 and hemangioma: In vascular endothelial cells, propranolol is considered to induce vascular contraction by suppressing NO production, inhibit renin production, control angiogenesis by regulating the expression of VEGF∙bFGF∙MMP2/MMP9, and induce apoptosis, but it may also affect pericytes and hemangioma stem cells [195–197].