The three TGF-β isoforms are present in human endometrial tumours. A) TGF-β1 and TGF-β2 immunoreactivity (green) was determined in human endometrial carcinoma tissues grade I, II and III and normal endometrial tissue, using Cybrdi human endometrial tissue array slides. Tissues were obtained by biopsies. Negative control staining was obtained by replacing primary rabbit anti-TGF-βantibodies with normal rabbit antiserum. Hoechst dye was used to visualize nuclei (blue). Results shown are representative of 17 grade I tumour specimens, 33 grade II tumour specimens, 5 grade III tumour specimens and 3 normal endometrial specimens. Magnification: 400×. B) Autocrine synthesis of each TGF-β isoform was determined in KLE endometrial carcinoma cells and HeLa cervical cancer cells using western blot. β-actin was used as a loading control.