PDCD1 and non-small cell lung carcinoma: More importantly, a correlation has been observed between tumor expression of PD-L1 and the likelihood of effectiveness of PD-1/PD-L1 blockade in NSCLC [14] and melanoma [15], suggesting that PD-L1 expression in tumor cells may predict or be related to the response to anti-PD-1/PD-L1 therapies.