FAS and Parkinson disease: Additionally, many of the genes upregulated in FAS microglia were also upregulated in the PD microglia, including CXCL8, FTH1, ATG4C and EDEM1 (Fig. 2d and Extended Data Fig. 5c), similar to a recent signature uncovered in iron-laden microglia in progressive MS lesions8,9 (Extended Data Fig. 6e).