CA9 and metastatic malignant neoplasm in the lymph nodes: Furthermore, low CAIX expression was significantly associated with the presence of lymph node metastases (odds ratio (OR) = 0.31, 95% CI = 0.15–0.62, P = 0.0009) and distant metastases (OR = 0.66, 95% CI = 0.46–0.96, P = 0.03) and predicted a higher tumor grade (OR = 0.41, 95% CI = 0.31–0.54, P<0.00001).