TOP1 and breast cancer: Brusatol was predicted to target 464 proteins, among which 46 are known targets of marketed drugs in cancer therapy (Supplementary Table S1), including the matrix metalloproteinase-1 (MMP1) and MMP8 for lung cancer30, 31, 32, MMP7 and chromodomain-helicase-DNA-binding protein 1 (CHD1) for primary breast cancer and prostate cancer33, TOP1 for metastatic colorectal cancer and extensive small cell lung cancer34, 35.