PTCH1 and medulloblastoma: Similar to Gli1/2 RNAi, Kapβ2 knockdown in SmoM2-induced medulloblastoma cells diminished the expression of Shh target genes, including Gli1, Ptch1, CycD1, and N-Myc (Fig 6F), leading to growth inhibition of the medulloblastoma cells as indicated by a cell survival assay (Fig 6G).