DNMT1 and acute myeloid leukemia: Second, we find that the dual SUMO1 and ubiquitin E3 ligase, TOPORS, is a key player in global-genome DPC repair that promotes degradation of 5-aza-dC-induced DNMT1-DPCs, which is in agreement with recent reports that identify a central role for TOPORS in response to hypomethylating agents in MDS and AML models (Truong et al, 2022; Kaito et al, 2023).