IL1B and supranuclear palsy, progressive, 1: Immunochemical analysis of brain tissue from patients with PSP showed activation and increased numbers of microglia in the substantia nigra compacta, subthalamic nucleus, pyramidal, and extrapyramidal motor systems, which correlated positively with tau burden, and upregulated expression levels of pro-inflammatory factors such as IL-1β were found in the substantia nigra (Gao et al., 2023).