POU5F1 and neoplasm: After culturing and separating of tumor spheres, we found that stemness associated genes (SOX2, OCT4, NANOG, and LIN28B) exhibited a high level of expression whereas stemness-suppressive microRNAs (let7 family and miR-146a) exhibited a low level of expression in spheres in accordance with previous studies (Supplementary Fig. 4A, B).