APOE and neoplasm: identified a unique pro-inflammatory and proliferative subpopulation of microglia, marked by upregulated expression of CX3CR1, NLRP1, IL1B, APOE, PDGFRA, and SOX2. The microglia were activated by TGF-β1 derived from SETD2-mut/IDH-WT tumor cells, and accelerated tumor progression via secreting IL-1β.