Remarkably, the selective inhibitor of GLS1 known as CB-839 presents in vitro antiproliferative activity against acute myeloid leukemia cells [258], and a panel of triple-negative breast cancer cell lines, but not estrogen receptor (ER) or human epidermal growth factor receptor 2 (HER2) positive cell lines, as well as in vivo efficacy in breast cancer xenograft models [107]. This evidence concerns the gene ESR1 and breast cancer.