Microglia are brain‐resident macrophages with important, but insufficiently understood functions in development, health, and disease. In a new exciting study, Wlodarczyk and colleagues uncover a transient subset of CD11c+ microglia that regulate CNS myelination via IGF‐1 expression. These findings represent not only the first evidence for a microglial role in myelinogenesis, but the first for a functionally distinct, genetically defined subpopulation of microglia.