CD274 and neoplasm: Similar to HER-2 positive tumors, claudin18.2 and PD-L1 co-expression is significantly decreased (p < 0.05) with co-expression of PD-L1 (defined as CPS ≥ 1) found in just 19.8% of patients with claudin18.2 expression of 2 + in 40% of tumor cells [75].