The intersection of microglial and macrophage biology in glioblastoma (GBM) and Alzheimer’s disease (AD) illuminates potential common and contradictory therapeutic avenues, particularly those associated with NF-κB signaling pathways, although these avenues are well-trodden, with an extensive research history. This evidence concerns the gene NFKB1 and early-onset autosomal dominant Alzheimer disease.