Syndecan-1 is an antigen of differentiation that is lost by carcinoma cells when these malignant cells are transiting from an epithelial to a less-differentiated mesenchymal phenotype (epithelial–mesenchymal tumoral transition, EMT) (Kato et al, 1995; Leppä et al, 1996 and reviewed in Larue and Bellacosa, 1996). This evidence concerns the gene SDC1 and carcinoma.