This body of evidence along with the finding the lack of microglia due to homozygous mutations in the CSF1R gene are associated with brain malformations, developmental delay, and epilepsy in humans (17), and new findings that microglia directly control neuronal activity through a negative feedback mechanism (41), suggest that microglia may be important to prevent and/or control the generation of epileptic networks. Here, CSF1R is linked to Global developmental delay.