CTLA4 and colorectal carcinoma: Twenty-four mice with MC38 peritoneal metastatic CRC were randomly divided into 4 groups, then received vehicle control, SB525334 (a TGF-βR inhibitor) alone, KN046 (a bispecific antibody that blocks both PD-L1 and CTLA-4) alone, or combined SB525334 and KN046 treatment (Figure 4A).