Does planar cell polarity signaling steer growth cones?

Recent studies established the role of planar cell polarity signaling in axon guidance. Signaling mechanisms controlling the direction of axon growth are poorly understood. The possibility that conserved and robust cell polarity signaling pathways may be reused as a key mechanism to convey asymmetric signaling in growth cones will provide insights to solving this long-standing mystery. Insights gained from growth cones can also shed light on general principles of cell polarity signaling. This review also discusses the possibility that this cell polarity signaling-based mechanism may be a general mechanism for mediating directional control by many, if not all, axon guidance molecules.