CLDN6 and cancer: The expression pattern of CLDNs varies among cancer types and the expression of CLDN6 has been explored from the perspective of pan-cancer analysis, in which CLDN6 was found significantly upregulated in 20 types of cancers while it is downregulated in glioblastoma multiforme (GBM), kidney chromophobe (KICH), kidney renal clear cell carcinoma (KIRC), acute myeloid leukemia (LAML), and brain lower-grade glioma (LGG) [48].