Fig. 2

The precision immunotherapy paradigm. GI cancers (star) escape the host immune response through the PD-1/PD-L pathway. Although the emergence of PD-1/PD-L blockade has renewed hope in immunotherapy, the response to PD-1/PD-L blockade is not as high as expected. The path toward precision immunology to improve efficiency includes six particularly important steps. The initial step in this process is to identify the population suitable for medication at the time of diagnosis for precision therapy. Once the drug is administered at the optimal time, the patient’s physical condition should be closely monitored, and side effects caused by the drug should be recognized in a timely manner. Concurrently, the efficacy of the drug should be properly evaluated. Upon disease progression, attempts should be made to overcome drug resistance to maintain efficacy. In addition, there is a need to improve the cost-effectiveness ratio to benefit more people. Through these efforts, precision immunotherapy of PD-1/PD-L blockade will become a reality