In this study, the expression profiles of ICOS, prognostic, immune-related level, tumor mutation burden (TMB), microsatellite instability (MSI), mismatch repair (MMR) genes, and DNA methyltransferases(DNMTS) were thoroughly analyzed at the pan-cancer level using data sets from the TCGA, GEO, and GTEx [22]. Here, ICOS is linked to neoplasm.