Furthermore, P-cadherin expression was positive in all mucinous carcinomas and carcinosarcomas a fact that points to a basal/myoepithelial cell histogenesis origin or line of differentiation of these tumour types [16,60,61], since P-cadherin is a well-recognized biomarker of basal mammary carcinomas in humans [6,62-65]. This evidence concerns the gene CDH3 and mucinous adenocarcinoma.