With the exception of T1338/T1338 cl1 (human cells survived in the mouse brains for 6 months but did not expand to generate a tumor), all SLGC lines generated orthotopic tumors in SCID mice, in which the human cells (revealed by the human-specific marker Stem 121) expressed high levels of Sox2, irrespective of the degree of cellular hierarchy observed in the xenotranspanted cultures. This evidence concerns the gene SOX2 and neoplasm.