ARG1 and lung cancer: In fact, the data have supported such a potentially important role for ARG1 in this process that a phase I/II clinical trial is currently underway (ClinicalTrials.gov NCT02903914) testing the efficacy of an ARG1 inhibitor (INCB001158) with or without anti–PD-1 antibody (pembrolizumab) for metastatic solid tumors, including non–small cell lung cancer (NSCLC) (19).