The proportion of TGF-β1–high tumors rose with the advancing stage: 45.4% (44/97) of non-invasive tumors, 73.8% (144/195) of early invasive and 77.7% (87/112) of muscle-invasive carcinoma overexpressed TGF-β1, with a highly significant difference between non-invasive and infiltrating urothelial carcinoma. This evidence concerns the gene TGFB1 and urothelial carcinoma.