HIF1A and neoplasm: IL-6, STAT3 and HIF1 mRNA levels in Hep2-CSC were significantly increased as compared to the IL-6, STAT3 and HIF1 mRNA expression levels in Hep2 cells and Hep2-derived tumor tissue, which were obtained from the tumor tissue after Hep2-cells were injected into dorsal area of nude mice (p < 0.001, Fig. 1a–c).