TK1 and cancer: Thymidine kinase 1 (TK1), a proliferation marker, has shown relevance in various cancers but its role in chemotherapy response for OC is unclear.<h4>Methods</h4>In this retrospective study, we assessed the association between TK1 protein (TK1p) and enzymatic activity (TK1a) and chemosensitivity (KELIM), platinum-free interval (PFI), and chemotherapy response score (CRS) in 28 patients with epithelial OC treated with platinum-based chemotherapy.