CD274 and squamous cell carcinoma: Multivariate analysis showed that squamous cell carcinoma (OR, 3.97; 95% CI, 1.82–9.11; P = 0.027) and PD-L1 expression < 1% (OR, 2.67; 95% CI, 1.17–6.24; P = 0.040) were significantly associated with an increased risk of LR.