GFAP and astrocytoma (excluding glioblastoma): To get insight into the function of these GFAP- isoforms in astrocytoma and to investigate a potential role for GFAPα and the GFAPδ/α ratio in astrocytoma malignancy, we modulated GFAP-isoform expression in U251-MG cells by recombinant expression or by silencing with shRNAs of the isoforms.