Comparison of 149 core promoters of TSS found to be consistently co-expressed with the novel PROM1 P6 promoter in at least four out of five CD133+ melanoma cell lines identified motif enrichment for Sp1 binding sites present in all PROM1 promoters, in agreement with their importance in the CpG islands located around P1–3 (Gopisetty et al., 2012). This evidence concerns the gene PROM1 and melanoma.