In this regard, it is important to note that underexpression levels, truncating or inactivating mutations in some HDACs in cancer have also been reported.18 Recently, Heideman et al.29 demonstrated that the reduction in HDAC1 and HDAC2 expression levels in vivo brings about T-cell lymphomagenesis owing to a block in the early thymocyte development. This evidence concerns the gene HDAC1 and cancer.