neointimal hyperplasia (EFO_0009652, an Experimental Factor Ontology id) is a hyperplasia due to proliferation and migration of vascular smooth muscle cells primarily in the tunica intima. It may develop after percutaneous coronary interventions such as stenting or angioplasty, and involves platelet aggregation at site of injury, recruitment of inflammatory cells, proliferation and migration of vascular smooth muscle cells, and collagen deposition, resulting in the thickening of arterial walls and decreased arterial lumen space. The term neointima is used because the cells in the hyperplastic regions of the vascular wall have histological characteristics of both intima and normal artery cells. Also known as: adverse neointimal proliferation, artery neointimal hyperplastic lesion, neointima formation, neointimal healing, neointimal hyperplasia after vascular injury, neointimal proliferation.