CA9 and metastasis: Increased levels of CA IX expression was significantly correlated with presence of metastasis (P=0.01); increasing Dukes' stage (P<0.01); lymphatic metastasis (P=0.01); vascular metastasis (P=0.05); lymph node metastasis (P=0.02); death (P=0.03) and recurrence (P=0.02), but not with tumour size, site, differentiation, gender or age of patients (P>0.05) (Table 1).