In the cerebellar white matter, P2RY12‐positive homeostatic microglia were more abundant than CD68‐ and TMEM119‐positive cells in the control cases, whereas they were present at similar levels to CD68‐ and TMEM119‐positive cells in MSA Stage I (Figure S5A–C,F). This evidence concerns the gene TMEM119 and multiple system atrophy.