CD274 and breast cancer: To date, PD-L1 expression remains the most studied biomarker for predicting responses to immunotherapy in various solid tumors, such as NSCLC,37 breast cancer,38 and esophageal cancer.39 We found no significant correlation between CD274 (encoding PD-L1) and S100A1 mRNA expression in TCGA-LUAD cohort (Supplementary Fig. 14b) or the mUC anti-PD-L1 cohort17 (Supplementary Fig. 14c).