We also examined the effects of combinations of SULF2 inhibitors and chemotherapy on cancer-initiating cells, as failure to eliminate these cells results in the failure of cytotoxic chemotherapy to eradicate metastatic TNBC.39,41–43 We found that upon treatment with chemotherapy alone, there was an enrichment of cancer-initiating cells, as assessed by flow cytometry, across all TNBC cell lines, while combination with the sulfatase inhibitor prevented their enrichment in the surviving fraction of cells. The gene discussed is SULF2; the disease is cancer.