CSF1R and Hereditary diffuse leukoencephalopathy with axonal spheroids and pigmented glia: Rademakers and colleagues were the first to show that the adult-onset hereditary leukoencephalopathy known as Hereditary Diffuse Leukoencephalopathy with Spheroids (HDLS) was caused by dominantly inherited, mono-allelic, CSF1R mutations (Rademakers et al., 2011).