The phase I ECHO-110 study was designed to test epacadostat at different doses combined with atezolizumab (i.e., an anti-PD-L1 agent) 1,200 mg Q3W in 29 patients with stage IIIB/IV NSCLC, who had previously been treated with ≥1 prior line of platinum-based chemotherapy (≥2 cycles), but not with checkpoint/IDO inhibitors. The gene discussed is IDO1; the disease is non-small cell lung carcinoma.