In previous human studies, the downregulation of these molecules was associated with the development of an aggressive invasive phenotype [61–63]; this is also relevant to carcinoma in dogs; for example, reduced E-cadherin expression is a common occurrence in canine mammary tumors and is associated with poor prognosis, including increased tumor proliferation and lymph node metastasis [64,65]. Here, CDH1 is linked to carcinoma.