SHH and central nervous system cancer: The prolonged survival times observed in the mice that received dnKif3a-expressing/cilia-depleted L0 cell implants may partly be due to the reduced responsiveness of these cells to endogenous SHH and/or reduced tumor stem cell proliferation, a possibility supported by studies showing that cyclopamine pre-treatment of certain GBM cell lines ablates the glioma stem cell pool, blocks its self-renewal, and inhibits tumorigenesis [4, 5].