PDCD1 and colorectal carcinoma: It is worth noting that the expression of HAVCR2 had a much closer relationship with high TBSS, among the other co-inhibitory receptor genes, including TIGIT, CTLA4, PDCD1 (PD-1) and LAG3, prompting us to further explore the role of HAVCR2 in the TGFβ-rich TME in CRC.