GFAP and astrocytoma (excluding glioblastoma): Two studies report absence of GFAP expression in proliferating cells as shown by the lack of GFAP expression in mitotic cells in astrocytoma of all grades (Schiffer, Giordana, Germano, & Mauro, 1986) and a lack of GFAP coexpression with the proliferation marker Ki67 in 15 low grade and 10 grade IV astrocytomas (Kros, Schouten, Janssen, & van der Kwast, 1996).