Systemic tumor cells with a hybrid phenotype, which is defined as primarily epithelial and moderately mesenchymal, represented the most aggressive cells, with enhanced ability to generate metastases, consistently with EpCAM function in cell adhesion, proliferation, and epithelial differentiation [131], and correlated with the occurrence of lung metastases in several types of cancer [101], such as in prostate, breast, bladder, and pancreatic carcinomas [96,125,126,132,133,134]. This evidence concerns the gene EPCAM and cancer.