The majority, 92.5% (37/40), of well- and moderately differentiated adenocarcinomas (Gleason scores 6 and 7) had negative or low Ki67 proliferative indices, while in the majority, 65.3% (66/101), of the poorly differentiated (Gleason scores 8-10), the indices were high. This evidence concerns the gene MKI67 and adenocarcinoma.