p53-deficient mouse embryonic fibroblasts (MEFs) gave rise to iPSCs using only two reprogramming factors, OCT3/4 and SOX226, and these cells acquired tumour-initiating ability in nude mice by a single oncogene30, suggesting that the loss of p53 changes the cell fate to TICs by oncogenic signals. The gene discussed is POU5F1; the disease is neoplasm.