ROBO4 and diabetes mellitus: ROBO4 has dual roles in vascular networks,11, 12, 13 and overexpression of ROBO4 inhibits vascular endothelial growth factor (VEGF)‐induced angiogenic signalling and increases vessel maturation in diabetes‐induced cerebral neovascularization,38 but it can accelerate the pathological angiogenesis in various tumours.