Although large-scale clinical data are still lacking for endometriosis, the established overexpression of FAP in endometriotic tissue and encouraging results from preclinical PET/CT studies using [18F]AlF-NOTA-FAPI-04—capable of distinguishing ovarian from peritoneal lesions—suggest that 99mTc-labeled FAPI tracers could represent a valuable tool for the noninvasive assessment of this condition in the near future. Here, FAP is linked to endometriosis.