CTAG1B and cancer: For example, in a study of 72 patients with grade 3 transitional cell carcinoma, 12.5% (nine patients) exhibited seropositivity for NY‐ESO‐1 antibodies, all of whom had either muscle‐invasive tumours or carcinoma in situ, while no antibodies were detected in patients with grade 1 or 2 tumours.41