Cxcr4 was identified as the top-ranked positive regulator of leukemia cells, with all 5 sgRNAs showing a median depletion of a fold change of more than 2.0 in vivo and with one sgRNA depleted more than 30-fold (5.1-fold depletion in log2 scale) (Figure 1C). The gene discussed is CXCR4; the disease is leukemia.