CA9 and cancer: For example, the percentage of CAIX (IHC) positive cases in 1229 different types of cancer cases was about 30%, with 0.0%, 12.0%, 29.0%, and 0.0% CAIX staining being reported for prostate adenoma and carcinoma, pancreatic carcinoma, lung adenocarcinoma, and thyroid follicular adenoma, respectively (46).