GFAP and brain neoplasm: The CD133-positive cells are much less in proportion compared to GFAP-positive cells in tumors formed by AGR53-GSC, DBT-Luc-GSCs, and MGG8-GSCs under FMOD nontargeting conditions (Figure 7—figure supplement 1A B, Figure 7—figure supplement 2A B, Figure 7—figure supplement 3A B), in good correlation to the low proportion of GSCs seen in brain tumors (Singh et al., 2004; Galli et al., 2004; Calabrese et al., 2007).