GCN5 is known as a subunit of the ATAC complex that regulates histone acetylation75–77, so the preferential loss of CSCs over non-CSCs upon GCN5/PCAF bromodomain inhibition using a small molecule inhibitor could serve as a potential candidate for targeted therapeutics if it represents sufficient specificity for certain cancer subpopulations and normal non-cancerous cells. The gene discussed is XCL1; the disease is cancer.