SHH and medulloblastoma: PF-04449913 inhibited sonic hedgehog (Shh) stimulated luciferase expression in mouse embryonic fibroblasts with an IC50 of 6.8 nM (Additional file 1: Figure S1b, c); and significantly reduced medulloblastoma growth in a Ptch1+/−p53+/− allograft model (Additional file 1: Figure S1d, e) at doses that decreased murine Shh target gene expression (Additional file 1: Figure S1f-h).