PDCD1 and colorectal carcinoma: A recent study showed that dual inhibition of TGF-β and PD1/PD-L1 with combination of ALK5i and anti-PD-L1 antibody, caused a significant increase in the frequency of CD3+T cells and enhanced the infiltration of CD8+ T cells in KPN liver tumor metastasis, a metastatic mouse model for CMS4 subtype of CRC (42).