Our group has demonstrated that one of the mechanisms underlying the invasive capacity of P-cadherin overexpression in breast cancer cells is mediated by the secretion of matrix metalloproteases (MMPs), which degrade the ECM during invasion (44, 45) and cleave P-cadherin extracellular domain to produce a soluble P-cadherin fragment (sP-cad). This evidence concerns the gene CDH3 and breast cancer.