Hsp90-IN-46 is an Hsp90 inhibitor demonstrating broad-spectrum antiproliferative effects on tumor cell lines. It suppresses the proliferation of breast cancer cells by reducing colony formation and downregulating the proliferation marker Ki-67. Hsp90-IN-46 inhibits Hsp90 and its ATPase activity, leading to the downregulation of oncoproteins HER2 and CDK4, while moderately inducing a heat shock response. In triple-negative breast cancer xenograft mouse models, it shows notable antitumor activity. Hsp90-IN-46 is applicable for research across various cancers, including triple-negative breast cancer, leukemia, non-small cell lung cancer, colon cancer, ovarian cancer, kidney cancer, and prostate cancer.