PROM1 and colorectal cancer: Additionally, CD133 expression has been reported in several solid tumours including retinoblastoma (Hemmati et al, 2003), glioblastoma (Singh et al, 2003, 2004), prostatic adenocarcinoma (Collins et al, 2005; Rizzo et al, 2005), kidney carcinoma (Florek et al, 2005), pancreatic cancer (Hermann et al, 2007) and colorectal cancers (O'Brien et al, 2007; Van Orden et al, submitted).