GFAP and astrocytoma (excluding glioblastoma): Hence we analyzed the IF meshwork in human astrocytoma U251-MG cells, constitutively expressing both GFAP-α and GFAP-ε, by expressing GFP-tagged wt and mutated GFAP-ε (GFP-GFAP-εwt vs. GFP-GFAP-εR430H).