DGKα-IN-2 (example 48) is a DGKα inhibitor with the IC50 of 0.9 nM, extracted from patent WO2021105115. DGKα-IN-2 significantly enhances the anti-tumor effect of anti-PD-1 by increasing the proliferation and function of T cells. DGKα-IN-2 has the potential for cancer and immunology study.