Nivolumab (Opdivo) is approved for the treatment of MSI-H/dMMR metastatic CRC. Nivolumab functions similarly to pembrolizumab, blocking the PD-1/PD-L1 interaction and enhancing the immune response against cancer cells. Nivolumab Plus Ipilimumab (Yervoy) combination therapy is approved for MSI-H/dMMR metastatic CRC. Ipilimumab targets CTLA-4, another checkpoint inhibitor, and when combined with nivolumab, provides a synergistic effect that enhances T cell activation and antitumor activity. PD-1 and its ligands play a critical role in the immune evasion mechanisms of colon cancer. ICIs targeting the PD-1/PD-L1 pathway have shown significant efficacy in treating MSI-H/dMMR colorectal cancer. Ongoing research aims to optimize these therapies, overcome resistance, and expand their use to benefit a broader patient population. The integration of PD-1 inhibitors with other treatment modalities holds great promise for the future of colon cancer immunotherapy. • PD-L1 | Liver cancer