On the other hand, hCA XII is abundant in many healthy tissues, like kidney, prostate, pancreas, intestine and lymphocytes, but overexpressed in a certain number of malignant tumours, and associated with less-aggressive, well-differentiated tumour phenotypes as compared to the hCA IX expressing tumours thus CA IX is the preferred isoform for pharmacological intervention7,.10–12. This evidence concerns the gene CA9 and neoplasm.