Chen et al. (32) performed immunogenomic analysis of PD-L1 expression level in TETs using the TCGA database; their results were similar to ours—PD-L1 protein expression was correlated with PD-L1 mRNA expression level and PD-L1 mRNA expression level differed (p = 0.0419) between TC (median 9.39) and thymomas (median 5.68), suggesting that high PD-L1 expression was considerably correlated with TET malignancy. Here, CD274 is linked to thymoma.