Summary of pairwise genetic interaction among all six RPTPs. Matrices depict role of RPTPs in CNS longitudinal axon guidance (a) and motor axon guidance (b). (c) Interaction of Ptp4E Ptp10D double mutant with RPTPs. Ptp4E shows enhancement of motor axon guidance phenotypes observed in Ptp10D Ptp69D and Ptp10D Ptp52F double mutants. Thicker lines indicate stronger genetic interaction than thinner lines. Red double headed arrows indicate synthetic genetic interactions. Black single headed arrows indicate enhancement/cooperation, and the blue lines indicate genetic suppression.