FACS analysis showed that compared with nonirradiated control cells, irradiated feeder cells led to more CD133+ cells dedifferentiated from CD133− cancer cells following 7 days coculture (P1: 3.4-fold induction (0.59% vs. 2.02%); P2: 5.2-fold induction (0.44% vs. 2.32%); P3: 16.2-fold induction (0.14% vs. 2.28%); PaTu8988: 5.1-fold induction (0.54% vs. 2.73%), Fig. 1a). This evidence concerns the gene PROM1 and cancer.