hCAI/II-IN-4 (compound 6d) is a powerful inhibitor of both hCA I and hCA II enzymes, with Ki values of 16.95 nM and 15.22 nM, respectively. It demonstrates inhibitory activity against hCA IX with a Ki value of 27.04 nM. Additionally, hCAI/II-IN-4 exhibits anti-hypoxia properties while maintaining low toxicity. This compound is suitable for investigating acute mountain sickness (AMS) in research studies [1].