GFAP and neoplasm: Inhibits self-renewal and induces differentiation of tumor stem cells in vitro (10 μM) and in vivo. Inhibits 5-LOX (19 μM). Reduces the GSLC pool through a decrease in the CD133+ population and abrogates clonogenicity. This occurs apparently via astrocytic differentiation, by up-regulating GFAP and down-regulating stemness related genes, rather than by inducing apoptosis of GSLCs.