PTBP1 and cancer: We identified 41 “age-down” microglial genes (Additional file 9 shows the gene list with fold change and p values), including well-known genes such as Man2b2, which encodes lysosomal acid α-D-mannosidase [24]; CYFIP1, which encodes a protein that functions in cytoskeletal remodeling to ensure proper dendritic-spine formation [25, 26]; Wasf2, another cytoskeleton regulator [27]; the inflammation-driven cancer gene Ptbp1 [28]; and toll-like receptor genes (Tlr5, Tlr9).