Xenotransplanted tumors originating from the four SCLC cell lines exhibited SCLC histological features and positive staining for ASCL1 in H209 cell-derived tumors, NEUROD1 in H82 cell-derived tumors, POU2F3 in H526 cell-derived tumors, and YAP1 in SBC3 cell-derived tumors (Figure 1B). The gene discussed is POU2F3; the disease is small cell lung carcinoma.