The generation of left-right organ asymmetry during development involves a
cascade of signaling events, while the initiating event is not proven, the
mechanism of such organ asymmetry involves a number of genetically defined
signaling molecules and, potentially specific transcription factors. Develo
pment of asymmetry appears to involve regulation of cell migration and prol
iferation events, and may be mechanistically distinct for different organs,
such as pulmonary asymmetry versus cardiac situs, While the precise mechan
isms by which genetically linked factors exert their effects still remains
incompletely defined, an outline of those events can be deduced.