Collectively, our results demonstrate the translational potential of 68Ga-FAPI PET/CT imaging in predicting or monitoring metastatic CRC response to immunotherapy and suggest that 68Ga-FAPI PET/CT may function as a noninvasive in vivo biomarker to guide precise TGF-β inhibition and improve clinical tumor response to immunotherapy. Here, TGFB1 is linked to neoplasm.