Fibroblast activation protein (FAP) plays an important role in changing the situation of the tissue and helps the tumor cells to attack the surrounding tissues. FAP receptor-defined tumors and cancer-associated fibroblasts (CAFs) play an important role in various aspects of malignant tumors such as migration, metastasis, resistance to chemotherapy, and immunosuppression. Therefore, targeting these cells might be useful for both imaging and treatment purposes. This receptor is expressed in various cancers such as bone, brain, breast, colon, esophagus, stomach, liver, lung, mouth, ovary, pancreas, kidney, etc.
The diagnostic radiopharmaceutical Ga-68-FAPI, produced by labeling the FAPI 46 peptide with gallium-68, intelligently detects FAP receptors, and tumors in which this type of receptor is expressed can be detected using positron emission tomography (PET).