HSP90AA1 and breast cancer: The inhibition resulted in the degradation of HSP90 clients in a dose-dependent manner without inducing HSR, which thereby showed the antiproliferative effect on MCF-7 breast cancer cells (IC50 = 0.60 μM).528 Apart from cucurbitacin D, other natural products were also reported to inhibit HSP90-P23 PPIs, including docosahexaenoic acid.