SHH and oligodendroglioma: SOX2 is also overexpressed or amplified in oligodendrogliomas and GBMs, and interestingly appears to be more highly expressed in the SHH-activated subgroup of medulloblastomas, perhaps suggesting a link between SHH and SOX2 signaling in a neoplastic context (Phi et al., 2010; Annovazzi et al., 2011; Ahlfeld et al., 2013).