CTLA4 and colorectal carcinoma: Moreover, in preclinical mouse cohorts of peritoneal or liver metastatic CRC, 68Ga-FAPI micro-PET/CT imaging–guided precise usage of SB525334, a TGF-β receptor type 1 (TGF-βR) inhibitor, significantly improved tumor responses to KN046, a bispecific antibody that bifunctionally blocks CTLA-4 and PD-L1.