Question:
Are there any other cells than glia that express GFAP?

Answer: (by Dr. S. Fedoroff, Dept. Anatomy & Cell Biol., College of Medicine, Univ. of Saskatchewan)
The cells that are GFAP positive in non-CNS tissues are cells in enteric ganglia and non-myelin-forming Schwann cells (Jessen et al., J Neurocytol 13:187-200, 1984; Dahl et al., J Histochem Cytochem 30:912-918, 1982), lens epithelium (Hatfield et al. J Neuroimmunol 8:347-357, 1985), Kupffer cells of the liver (Gard et al., Soc Neurosci Abstr 8:240, 1982) and some cells in salivary tumors (Nakazato et al., Lab Invest 46:621-626, 1982). ... also erythrocytes may have GFAP positivity.