Fibroblast Activation Protein (FAP) is an enzyme that is primarily found on the surface of certain cells, particularly in the connective tissue. It plays a crucial role in tissue remodeling and repair by breaking down proteins in the extracellular matrix. FAP is often associated with fibroblasts, which are cells that produce collagen and other fibers essential for maintaining the structure of tissues. In addition to its role in normal tissue function, FAP is also implicated in various diseases, including cancer. Tumors can exploit FAP to promote their growth and spread by remodeling the surrounding tissue. As a result, FAP has become a target for potential therapeutic interventions and diagnostic imaging in oncology.