More recently, major treatment responses have been observed with the use of immune checkpoint inhibitor proteins expressed on the surface of lymphocytes and other immune cells, most notably on cytotoxic T-cells. When bound to their specific ligand, often another surface-bound protein on a neighboring cell, they can transmit stimulatory or inhibitory signals to activate or inhibit the cellular adaptive immune response. Several studies showed that the predominant mechanism by which NSCLC evades detection and elimination by the immune system is by exploiting one such inhibitory pathway through the expression of programmed death ligand 1 (PD-L1, B7-H1). PD-L1 then binds to its receptor, programmed cell death protein 1 (PD1), on surveilling lymphocytes and initiates a signaling cascade which leads to lymphocyte exhaustion, a state of impaired function. The most successful immune checkpoint inhibitors so far are anti PD1 or anti-PD-L1 monoclonal antibodies that prevent PD1-PD-L1 interaction at the tumor-immune interface. In this pilot study, the investigators will investigate if Nilogen's functional ex vivo bioassay can predict therapeutic response to anti PD1 (nivolumab, pembrolizumab) or anti PD-L1 (atezolizumab) in advanced non-small cell lung cancer (NSCLC).