Importantly, GLV-1h254-infected cells found in whole blood samples from human cancer patients with metastatic breast cancer, colorectal cancer, lung cancer and melanoma and from mice bearing human lung and prostate tumors were confirmed to be CTCs by immunostaining for epithelial cell biomarkers, such as CK and EpCAM, or tumor-specific antigens. This evidence concerns the gene EPCAM and colorectal cancer.