As mentioned above, there are several limitations identified, including the fact that EpCAM is also expressed on normal epithelial cells, raising concerns about potential off-target effects and toxicity [146]; the dynamic expression of EpCAM during tumor progression might affect therapeutic efficacy [121,147,148]; and its expression differs among various tumor types, as well as between primary and metastatic tumors [86,180]. The gene discussed is EPCAM; the disease is metastatic neoplasm.