Mutations in Csf1r, resulting in reduced macrophages, consistently lead to hydrocephalus in Csf1r−/− mice, 1‐year‐old Csf1r+/− mice and humans with biallelic CSF1R mutations, indicating a protective role of cpMs in fetal and childhood hydrocephalus [126, 127, 128]. This evidence concerns the gene CSF1R and Hydrocephalus.