CSF1R and Hereditary diffuse leukoencephalopathy with axonal spheroids and pigmented glia: We first isolated dermal fibroblasts from skin biopsies taken from two patients with HDLS and confirmed mutations in the TDK region of the CSF-1R gene (HD1, HD2; clinical characteristics shown in Supplementary file 1, table S1) then cultured them for approximately 4 weeks before reprogramming into induced pluripotent stem cells (iPSCs) (Figure 1A).