SOX2 and medulloblastoma: Along with well-established BTIC markers such as Nestin, Vimentin, Sox2 and OCT3/4 [10, 13, 14], we found OTX2 – a medulloblastoma oncogene [17], which we documented previously as an early marker of primitive neuroectoderm and BLBP - an established marker of RG cells, to be highly expressed in the TCL self-renewing cells [9].