MMP9 and hemangioma: ↓ proliferation and ↑ apoptosis in HUVEC (Xie et al., 2013)↓ VEGF and MMP-9 in hemangioma-derived EC (Storch and Hoeger, 2010) ↓ endoglin, ACVRL1, PAI-1 in HMEC-1 and HUVEC (Albinana et al., 2012)