CLDN6 and glioblastoma: In the present study, to assess the expression level of CLDN6 across pan-cancer, we examined CCLE database, TCGA database, and GTEx database and found that it was significantly upregulated in 20 types of human cancers, including ACC, BLCA, BRCA, CHOL, COAD, ESCA, HNSC, LIHC, LUAD, LUSC, OV, PAAD, PCPG, READ, STAD, TGCT, THCA, THYM, UCEC, and UCS, while it was downregulated in GBM, KICH, KIRC, LAML, and LGG.