UNG expression was negatively correlated with APOBEC3B expression in mature B cell lymphoma cell lines (MATBCL; ρ = − 0.372, padj = 0.034, n = 60, Ntests = 230) and with APOBEC3A expression in chronic lymphocytic leukemia cells (CLLE; ρ = − 0.324, padj = 0.037, n = 78, Ntests = 230). The gene discussed is APOBEC3B; the disease is B-cell non-Hodgkin lymphoma.