Class 3 semaphorin in angiogenesis and lymphangiogenesis.

Semaphorins were originally identified as axon guidance molecules involved in the development of the neuronal system. However, accumulating evidences have clearly demonstrated that the semaphorin system is not restricted to the brain but supports functions of other organs. Here, we review the rapidly emerging functions of sempahorins and, in particular class 3 semaphorin, in vascular and lymphatic systems during the development, tumor angiogenesis and ischemic revascularization.