  The complex nature of filling factor $\nu$=0 of monolayer graphene is studied
in magnetotransport experiments. As function of perpendicular magnetic field a
metal-insulator transition is observed, which is attributed to disorder-induced
Landau level broadening in the canted antiferromagnetic phase. In the metallic
regime a separation of the zeroth Landau level appears and signs of the quantum
spin Hall effect are seen near $\nu$=0. In addition to local transport,
nonlocal transport experiments show results being consistent with helical edge
transport.
