In addition, pembrolizumab efficacy data on the cohort of PD-L1 positive patients diagnosed with NENs recruited into the KEYNOTE-028 study were presented in ESMO 2017 Annual Conference (16 patients) and showed promising results (objective responses were observed in four patients: one patient with pNET and in 3 carcinoid patients)[24]. Here, CD274 is linked to carcinoid tumor.