Although the role of CSCs and P-cadherin in the metastasis needs to be further clarified, we believe that P-cadherin, as well as α6 and β4 integrin receptors, possibly in combination with other CSC markers, could be explored to better define the CSC phenotype of breast carcinomas or other malignant tumours and their corresponding metastasis. This evidence concerns the gene CDH3 and cancer.