HSP90AB1 and autosomal dominant polycystic kidney disease: To check whether H2-GMZ targets Hsp90 client proteins for degradation via the proteasome pathway, we treated primary human ADPKD cells with H2-GMZ for 24 h in the presence or absence of the proteasome inhibitor MG132 and determined the levels of Hsp90 client proteins in the detergent (Triton X-100)-soluble and -insoluble fractions from the cell lysate.