Han et al. reported a concept to consider cilia in tumor biology, in which genetic ablation of primary cilia blocked medulloblastoma formation in conditions under which this tumor is driven by a constitutively active Smoothened protein, an upstream activator of Hedgehog signaling, whereas removal of cilia is required for medulloblastoma growth by a constitutively active glioma-associated oncogene family zinc finger-2 (Gli2), a downstream transcription factor [16]. The gene discussed is GLI2; the disease is neoplasm.