CX3CL1 and Parkinson disease: Co-localization studies revealed that the staining intensity of perikaryal CX3CL1-immunoreactivity in neurons without α-syn immunoreactive (α-syn-ir) or AT8 immunoreactive (AT8-ir) aggregates was similar across MMD-LB, PD, and PSP groups (Figures 2D–L) as compared with the control group (Figures 2A–C).