However, we have previously demonstrated that the multi-lineage outgrowths derived from t-hESCs have hallmarks of neoplastic teracarcinomas with higher self-renewal that teratomas and poor differentiation [13, 16] and we now find teratocarcinomas from t-hESC are less sensitive to radiotherapy and continued to contain cells that expressed Oct-4, suggesting the maintenance of multi-potent population within the tumour following radiation. The gene discussed is POU5F1; the disease is teratoma.