CD274 and non-small cell lung carcinoma: In 2014, the first two ICIs (nivolumab (NCT01721772) and pembrolizumab (NCT01295827)) targeting PD-1 were approved by the FDA for malignant melanoma [199,200], and, in 2015, nivolumab emerged as a novel second-line treatment in advanced squamous cell and NSCLC patients regardless of PD-L1 expression level (CheckMate 017, CheckMate 057) [201,202] (Table 2).