PDCD1 and non-small cell lung carcinoma: Data from literature suggest that, although the overall response rate (ORR) to Nivolumab in NSCLC is higher in patients with PD-L1 positive tumors compared to PD-L1 negative, still most PD-L1 positive tumors do not respond to anti-PD-1 directed immunotherapy, nor does lack of PD-L1 expression exclude the possibility of response16, 17.