Elevated expression and secretion of TNF-α from activated microglia are believed to facilitate conversion of astrocytes into cytotoxic subtype and play a direct role in PD and AD (Liddelow et al., 2017), whereas exogenous IL1β has been reported to stimulate proliferation and reactivity of microglia (Todd et al., 2019). The gene discussed is IL1B; the disease is Alzheimer disease.