CD274 and gastric cancer: Pembrolizumab monotherapy at the salvage line for advanced GC demonstrated higher benefits in patients with PD-L1-positive than in patients with PD-L1-negative [35], whereas the ATTRACTION-2 study demonstrated the benefit of nivolumab monotherapy regardless of the PD-L1 expression levels although PD-L1 TPS was determined only in a limited number of patients [13].