Furthermore, inhibition of another common enzyme in the TME, arginase 1 (Arg1), using the small molecule inhibitor CB-1158 (clinical trials in combination with checkpoint inhibitors for advanced solid tumors- NCT02903914), was also shown to activate NK cells, promote their infiltration into the TME, and synergize with checkpoint inhibition to promote tumor clearance. The gene discussed is ARG1; the disease is neoplasm.