For example, the transcriptome of a subgroup of supratentorial ependymoma with amplified EPHB2 and CDKN2A loss (subgroup D) closely matched that of embryonic cerebral Cdkn2a−/− NSCs, whereas spinal ependymomas resembled adult wild-type NSCs from the spinal cord. The gene discussed is CDKN2A; the disease is ependymoma.