Pax-8+ alerts to the development of renal tumors (renal cell carcinoma and renal collecting duct carcinoma), Müllerian duct tumors, and thyroid tumors; other positively expressing tumors include thymoma/carcinoma and pancreatic neuroendocrine tumors, and other malignant diseases. Pax-8 is a transcription factor associated with the development of fetal brain, eye, thyroid, kidney, upper urinary tract system, and organs of Müllerian origin, and it is involved in renal cell differentiation, thyroid development, or thyroid dysplasia, and therefore plays a key role in fetal development and cancer growth. For patients whose examination finds Pax-8+, it is recommended that they go to regular hospitals to improve PET-CT and other related examinations, and if malignant lesions are found in the examination, they need to follow the doctor’s instructions for treatment as early as possible in order to improve the quality of life.