Immunostaining adenocarcinoma in situ and minimally invasive adenocarcinoma using an anti-TGF-β1 antibody. (a) TGF-β1-positive MIA sample. TGF-β1-positive cells are stained brown. TGF-β1-positive cells are predominantly observed in the tumor itself. This sample has an Allred score of 6/8; (b) TGF-β1-negative AIS sample. This sample has an Allred score of 0/8. TGF: Transforming growth factor; AIS: Adenocarcinoma in situ; MIA: Minimally invasive adenocarcinoma.