PICALM and Alzheimer disease: Interestingly, a mild increase in ROS can be neuroprotective by the formation of glial lipid droplets that transfer peroxidized lipids from neurons to glia, where homologs of AD-risk genes ABCA1, ABCA7, VLDLR, VPS26, VPS35, AP2A, PICALM, and CD2AP are required in Drosophila [214].