HGFAC and medulloblastoma: CSCs in FSmoM2;hGFAP-cre medulloblastomas depend on bFGF/EGF and not SHH, similar to their cell of origin (NSCs), and they are insensitive to SHH inhibition (18), even though the SHH pathway is highly activated in bulk tumor cells in this model (Supplementary Fig. S1A).