In Drosophila, neuronal mitochondria that lack OXPHOS generate ROS-protective fatty acids and lipid droplets in associated glia. In this issue, Liu et al. (2017) demonstrate that neuronal lipid synthesis is driven by the glial lactate shuttle. This lipoprotein-dependent deposition of lipids may be at the origin of glial specializations evolving in vertebrates. In Drosophila, neuronal mitochondria that lack OXPHOS generate ROS-protective fatty acids and lipid droplets in associated glia. In this issue, Liu et al. demonstrate that neuronal lipid synthesis is driven by the glial lactate shuttle. This lipoprotein-dependent deposition of lipids may be at the origin of glial specializations evolving in vertebrates.