C9 and Parkinson disease: Yamada et al. [21] reported staining of Lewy bodies in the PD substantia nigra for both early-stage (C3d and C4d) and late-stage (C7 and C9) complement proteins, and C3d and C4d staining on Lewy bodies was subsequently reported in the brain stem from subjects with dementia with Lewy bodies (DLB) [22].