CD81 and neoplasm: Thus, targeting DNA hypermethylation through chemical inhibitors of DNA methyltransferases, such as 5-Aza-CdR or HDAC inhibition via Trichostatin A, may provide a means to restore expression of many tetraspanins and their anti-tumor functions in various carcinomas, such as CD82 and CD151 in prostate cancer and CD81 in neuroblastomas or glioblastomas [148,149,163,164,165].