To address this question in an unbiased manner, we performed genome-wide CRISPR knockout screens in the NALM-6 pre-B cell lymphoma line with the previously reported EKO sgRNA library (Bertomeu et al., 2018) to identify genes that exhibit synthetic lethality with the loss of UBE2R1 and/or UBE2R2. The gene discussed is CDC34; the disease is B-cell non-Hodgkin lymphoma.