APEX1 and lymphoma: An analysis of the mRNA levels of uracil excision repair factors in CAG-A3B lymphomas indicates positive associations between APOBEC signature enrichment and uracil DNA glycosylase 2 (Ung2), AP endonuclease 1 (Apex1), and X-ray repair cross-complementing protein 1 (Xrcc1), but not with Rev1 (Figure 5B-E).