Abstract: Thymidine kinase 1 (TK1), an enzyme of the pyrimidine remedial pathway, can catalyze phosphorylation of thymidine to thymidine monophosphate. It is closely related to cell cycle regulation and cell proliferation. A number of experiments show that TK1 can be used for physical examination, tumor screening, routine testing, effect monitoring and prognosis, which is considered to be a sensitive and useful marker for human tumor growth.

Key words: Neoplasms, Thymidine kinase, Immunohistochemistry