In vitro assays of EphB2 overexpressing Ink4a/Arf(−/−) STeNSCs showed no changes in their neural stem cell characteristics (stem cell marker expression and self-renewal) upon receptor activation, but EphB2 driven tumor cells were inhibited significantly in differentiation and exhibited increased tumorsphere formation and cellular proliferation in response to ephrin-B ligand mediated receptor activation. The gene discussed is CDKN2A; the disease is neoplasm.