To this end, Chen et al. performed cell-based screenings with a compound collection to identify new therapeutic agents against MLL-rearranged leukemia cells and identified rabeprazole, a proton pump inhibitor used for heartburn, acid reflux and gastro-esophageal reflux disease (GORD), as a candidate for inhibiting the growth of MLL-rearranged cell lines but not MLL wild type cells (Chen et al., 2020). The gene discussed is KMT2A; the disease is gastroesophageal reflux disease.