CD274 and esophageal squamous cell carcinoma: A KEYNOTE-181 phase III randomized trial compared pembrolizumab plus chemotherapy to chemotherapy alone in 628 patients with previously treated advanced EC (63% with ESCC), showing that ESCC patients (with a PD-L1 CPS of ≥ 10) had an OS of 43% after 12 months with pembrolizumab plus chemotherapy compared with 20% with chemotherapy alone and a median OS of 8.2 months using pembrolizumab plus chemotherapy compared with 7.1 months with chemotherapy alone [97].