Thus, zinc finger E-box-binding homeobox (ZEB), an E-box transcriptional repressor involved in the induction of tumor cell EMT, has been shown to negatively regulate the expression of the co-stimulatory molecule CD4 in CD4 single-positive T lymphocytes [119] and to act as a transcriptional repressor of IL-2 by binding to the IL-2 promoter [120] and as a repressor of the immunoglobulin heavy chain enhancer [121]. This evidence concerns the gene CD4 and neoplasm.