STAT3 and Parkinson disease: In prodromal PD CSF, single-cell RNAseq analysis revealed increased frequencies of a population of microglia like macrophages, termed CSF Mac, exhibiting inflammatory responses characterized by increased expression of IL6-JAK-STAT3 and TNFRSF1A and TNFRSF1B signaling pathways, with a prominent lack of T cell activation.