CA9 and neoplasm: A relationship between CAIX tumour tissue expression, as detected by immunohistochemistry (IHC) and patient outcome has been reported in a wide variety of tumours (Bui et al, 2003; Hedley et al, 2003; Trastour et al, 2007; Choi et al, 2008; Klatte et al, 2009; Korkeila et al, 2009).