TDP2 (tyrosyl-DNA phosphodiesterase 2) is a 5'-tyrosyl-DNA phosphodiesterase that serves dual roles in DNA repair and viral pathogenesis. Primarily, TDP2 excises topoisomerase II-DNA adducts by cleaving covalent protein-DNA crosslinks generated during topoisomerase-mediated DNA metabolism 1. This repair function coordinates with non-homologous end joining (NHEJ) pathway components Ku and ligase IV 1. Additionally, TDP2 contributes to suppressing genomic instability caused by DNA-protein crosslinks through ubiquitylation-dependent mechanisms working alongside SPRTN and PARP1-driven pathways 23. Clinically, TDP2 is essential for picornavirus replication, removing the VPg (viral protein genome-linked) primer from viral RNA 5'-ends 1. Mutations in TDP2 cause spinocerebellar ataxia type 23, suggesting critical roles in neuronal function 4. TDP2 represents a therapeutic target: inhibition synergizes with topoisomerase II inhibitors (etoposide, doxorubicin) in cancer treatment, while TDP2 inhibition may prevent viral replication 15. Post-translational modifications fine-tune TDP2's regulatory networks for optimal repair efficiency 67, positioning TDP2 as a multifunctional enzyme bridging genome stability and host-pathogen interactions.