Although P-cad overexpression has been implicated in sustaining malignant phenotypes in fully transformed breast cancer cells (Vieira and Paredes, 2015), our observations suggest that P-cad could also play a major role in the very early stages of breast carcinogenesis by promoting a transient boost of MRTF-A–SRF signaling pathway activity, essential for the acquisition of pre-malignant and malignant phenotypes. This evidence concerns the gene CDH3 and breast carcinoma.