KEYNOTE-012, which recruited patients with ≥1 % PD-L1 tumor cell positivity to receive pembrolizumab 10 mg/kg Q2W for up to 24 months, included head and neck cancer [23], gastric carcinoma [24], urothelial carcinoma [25], and triple-negative breast cancer [26] (Table 1). Here, CD274 is linked to head and neck cancer.