CA9 and breast cancer: Although other members of the CA gene family have been examined in several tumour types (Nogradi, 1998), and it is known that the increased expression of CA IX is associated with aspects of early tumourigenesis in cervix, colon and lung tumours (Liao and Stanbridge, 1996; Saarnio et al, 1998; Vermylen et al, 1999), a prognostic role for CA has not previously been identified in breast cancer.