TPBG is a transmembrane glycoprotein rich in leucine, involved in cell adhesion. It is widely expressed in various nourishing layer cells during embryonic development. In adults, this protein is highly expressed in many tumor cells, such as uterine cancer, colon cancer, stomach cancer, ovarian cancer, oral cancer, prostate cancer, lung cancer, or kidney cancer, and is associated with poor clinical outcomes in many cancers. Therefore, it is a suitable tumor target.