YAP1 and medulloblastoma: On the other hand, the Yap controls the cell density to regulate Hh signaling (Tariki et al. 2014), Yap regulates neuronal differentiation through Shh signaling (Lin et al. 2012), and Yap1 is amplified and up-regulated in Hh-associated medulloblastomas and mediates Shh-driven neural precursor proliferation (Fernandez-L et al. 2009).