GLI1 and central nervous system cancer: Although SMO is important to mediate the hedgehog signal in Glioma cell as well as the activator of GLI, but still it is worth to mention that only the inhibition on SMO by external drug to Glioma cell is not sufficient to shut down the abnormal over expression of GLI proteins completely, there may be some other intracellular proteins in the cytoplasm that have the potential to activate or over express the GLI proteins without the help of SMO.