CD274 and viral infectious disease: The main reasons were the absence of PD-L1 expression (n = 18; 7.5%), persistent CRT-related toxicities (n = 14; 5.9%), disease progression (n = 24; 10%), denial of consent (n = 2; 0.8%), death due to other causes (n = 2; 0.8%), viral infections (n = 5; 2.2%, including SARS-CoV-2), and acute renal injury (n = 1; 0.4%).