It is an immunofluorescence based test, using three monoclonal antibodies, two of them (M344 and LDQ10, labelled with fluorescein green) are directed against mucin-like antigens related to urothelial carcinoma.17,18 They were found to be positive in 71% of non-invasive (pTa) or early invasive (pT1) tumours. This evidence concerns the gene MUC5AC and urothelial carcinoma.