DGKα-IN-4 (example 432) is a DGKα inhibitor with the IC 50 of 0.1 nM, extracted from patent WO2021105117. DGKα-IN-2 significantly enhances the anti-tumor effect of anti-PD-1 by increasing the proliferation and function of T cells. DGKα-IN-3 has the potential for cancer and immunology study.