Cardiac development: new concepts.

Understanding normal development is a prerequisite to unraveling the mechanisms that underlie congenital heart disease, a critical step if one is to design rational new therapies. Over the past 20 years, human molecular genetics and developmental biology have provided a group of powerful tools to uncover a number of now well-defined pathways. There is now a confluence of new technologies and experimental systems that may allow for a more profound understanding in the near future.