CSF1R and Hereditary diffuse leukoencephalopathy with axonal spheroids and pigmented glia: Identification of common mutations in the kinase domain of CSF1R, a gene that regulates mononuclear cell lineages, including microglia in both HDLS and POLD (1), has provided additional evidence that HDLS and POLD should be regarded as a single disease entity (10, 11).