Notably, a primary resistance is observed in about 70 to 80% of cases and a majority of responder patients will ultimately relapse as a consequence of several mechanisms that are either extrinsic or intrinsic to the tumor cell.6 Only recently have elegant studiesreported that the ability of anti-PD-1 mAb in lowering lung tumor growth largely depends on specific community structure within gut microbiota at baseline. Here, PDCD1 is linked to neoplasm.