hCAIX-IN-16 (Compound 12d) is hCA IX inhibitor, with Ki values of 190.0 and 187.9 nM for hCA IX and hCA XII, respectively. hCAIX-IN-16 can arrest the cell cycle of breast cancer MDA-MB-468 in G0-G1 and S phase and induce apoptosis. hCAIX-IN-16 shows good broad-spectrum anticancer activity and can be used for cancer research[1].