Liu et al100 demonstrated that during the transition from adenocarcinoma to undifferentiated small-cell carcinoma, POU5F1, lin-28 homolog A (LIN28A), SOX2, and NANOG are sequentially activated, driving the transformation of differentiated adenocarcinoma to undifferentiated small-cell carcinoma. The gene discussed is POU5F1; the disease is adenocarcinoma.