Intriguingly, Ppy-lineage beta cells became dominant also in Ppy-Cre;Rosa26-YFP;Ins-TR1 mice 5 weeks after DT administration (Fig. 6e,f), suggesting that Ppy-lineage beta cells are more resistant to prolonged hyperglycaemia than non-Ppy-lineage beta cells. The gene discussed is PPY; the disease is Hyperglycemia.