POU5F1 and lung cancer: Remarkably, our data indicated that compared with either single agent, co-treatment of elemene and gefitinib caused a marked decrease in the expression of stem-related genes including sonic hedgehog (SHH), hairy and enhancer of split (HES)1, NOTCH1, c-Myc, SRY-box (SOX)2 (though to a less extent) and octamer-binding transcription factor (OCT)4 in lung cancer cells (Figures 4A,B).