PDCD1 and non-small cell lung carcinoma: Compared with EGFR and ALK, PD-L1 is relatively novel; arguably, the advent of anti-programmed death cell protein-1 (PD-1) and anti PD-L1 are the most important innovations in the past decade; these innovations have proven to evade the immune system and promote remarkable antitumor activity in NSCLC [4,6].