Thymidine Kinase
Thymidine kinase (TK) belongs to the group of oncofetal enzymes. It catalyzes thymidine transformation to thymidine monophosphate in the presence of ATP. Elevated serum levels of TK can be found above all in the acute stages of malignant diseases of the hematopoietic system, in the bronchoendogenic carcinoma, carcinoma of the prostate, testis, and bladder.