It was suggested that MUC1, a mucin detected in an important proportion of prostate cancers (Kirschenbaum et al, 1999), was associated with a decrease of cell to cell (Ligtenberg et al, 1992) or cell to extracellular matrix (van de Wiel-van Kemenade et al, 1993; Wesseling et al, 1996) interactions, by masking cellular adhesion molecules. This evidence concerns the gene MUC1 and prostate carcinoma.