**6. Conclusions**

Immune checkpoint molecules are promising for cancer immunotherapy. Each has specific structure and specific ligands that can be engineered in such a way that immune-suppressing activity is redirected into immune-activating activity either as monotherapy or in combination with other checkpoints to help in tumor growth reduction. PD-1 and CTLA-4 are the two most common checkpoints with FDA approvals for several cancers, years ahead of other checkpoints. TIGIT and LAG-3 are also known to show promising potential in cancer immunotherapy. As in the context of cancer immunity, immune checkpoint molecules favor cancers by facilitating mechanisms that may support cancer growth or help to negate the effects of checkpoint molecules via inhibitory mechanisms. Combination of checkpoint molecules has also been shown to outperform single checkpoint therapy. However, immune checkpoint-based immunotherapy requires proper monitoring and management for adverse effects and exudes minimum risk to patients.
