CX3CR1 and Parkinson disease: While all three of these markers are considered “homeostatic” markers, their expression can change in disease-associated and inflammatory states (Kenkhuis et al., 2022) and infiltration of peripheral macrophages into the brain in diseases like Parkinson's disease and multiple sclerosis (Prinz and Priller, 2017) could complicate the analysis of morphology in datasets stained with nonspecific markers such as Cx3cr1 and Iba1.