Semaphorins are secreted, transmembrane, and glycosylphosphatidylinisotol-anchored glycoproteins that are important in cell to cell signaling. Humans have 20 semaphorins, the most of any species analyzed to date. Their role was originally identified in the development of the nervous system and axonal guidance. Since then, they have been shown to be important in the development and functioning of many tissues including: Continue reading →