PROM1 and hepatocellular carcinoma: Among 19 transcription factors that regulate CD133 gene expression and were identified via a TRANSFAC database-based prediction, three candidates, FOXP3, c-Myc, and AP-2α, were identified via a Venn diagram approach; that is, these three candidates were found at the intersection of all the sets in the Venn diagram and might mediate the effect of the POSTN protein in promoting HCC cells to acquire the CD133 phenotype (Fig. 3C).