Double face of VEGF.

The Roman god Janus (Figure) was the guardian of gates and doors and was believed to represent beginnings and endings; he is hence represented by a double-faced head. He particularly presided over all that is double-edged in life and represented the transition between the primitive and civilization, between the countryside and the city, peace and war, and the growing-up of young people. The controversy over vascular endothelial growth factor’s (VEGF) role in pathologic angiogenesis and the transition from a healthy to a diseased state is thus symbolized to a certain extent by the “gatekeeper” function that Janus played in Roman mythology.