Vascular smooth muscle diversity: insights from developmental biology.

Vascular smooth muscle exhibits remarkable structural and functional diversity. For many years, this diversity was thought to be due to plasticity of a single type of smooth muscle cell responding to biologic and mechanical variations in the local environment. However, recent studies of vascular development employing novel lineage mapping and mouse mutagenesis approaches suggest that much of the smooth muscle diversity found in adult blood vessels may have a developmental basis.