All compounds are evaluated under normoxic and anoxic conditions against different cell lines such as MRC-5 (human foetal lung fibroblast cells, normal lung cell), HCT-116 (human colorectal cancer cell line, which does not express hCA IX in response to anoxia), MDA-MB-231 (human breast carcinoma cell line, CA IX negative), and HT-29 (human colon carcinoma cell line, overexpressing high amounts of CA IX), but without any data regarding the binding affinity against hCA IX. Here, CA9 is linked to breast carcinoma.