The low specificity of BTA results in the inability to distinguish bladder cancer from bacterial cystitis or haemorrhagic cystitis.28, 29 On the other hand, the TK1 activity test and B‐raf proto‐oncogene serine/threonine kinase gene mutation test have high specificities and low sensitivities, suggesting that it can be used to confirm malignant tumours.21, 22, 23, 30 A high sensitivity test is suitable as a screening tool, and depending on the result, additional tests may be needed to confirm the diagnosis. This evidence concerns the gene TK1 and cancer.