GFAP and neoplasm: As mentioned earlier, a cell with both GFAP and vimentin is an aggressive tumor cell (91, 123–125), a cell with Iba1 and vimentin is an activated macrophage or microglial cell (71, 74, 127), and a cell with Iba1 and GFAP is either a macrophage or microglial cell that phagocytosed a GFAP expressing cell (astrocyte or tumor cell) or a cell type with a dual astrocytic and macrophage/microglia molecular phenotype (75–77, 79, 122).