PD-1/PD-L1 Inhibitor 3 is primarily used in cancer immunotherapy to enhance the body's immune response against tumors. It works by blocking the interaction between PD-1, a protein on immune cells, and PD-L1, a protein on cancer cells. This inhibition prevents the cancer from evading immune detection, allowing T-cells to recognize and attack tumor cells more effectively. It is particularly promising in treating cancers such as melanoma, non-small cell lung cancer, and renal cell carcinoma, where PD-L1 expression is high. The compound is being studied in clinical trials to evaluate its efficacy and safety as a standalone treatment or in combination with other therapies. Its potential to improve patient outcomes makes it a significant focus in oncology research.