“…Circulating TK1 activity correlates with the presence of disease, proliferative capacity and/or clinical stage/sub‐stage for many human haematopoietic tumours including lymphoma (LSA), 5–9 multiple myeloma, 10–12 leukaemias 13–17 and myelodysplastic syndromes 17,18 . While TK1 activity appears to be elevated less frequently in people with solid tumours, elevations have been detected in patients with carcinomas of lung, breast, prostate, gastrointestinal tract and cervix among others 7,19–25 . Furthermore, both one‐time and serial TK1 measurements may have prognostic or predictive value in human leukaemia, LSA and multiple human carcinomas 5–12,25 .…”