To analyze the transcriptional machinery of CD133 gene, we used a human colon carcinoma cell line Caco-2 and a human synovial sarcoma cell line Fuji, because both cell lines express abundant CD133 transcripts and proteins, and also CD133+ Caco-2 cells are reported to be able to generate tumors following transplantation in mice, whereas CD133- cells are not [36]. This evidence concerns the gene PROM1 and synovial sarcoma.