HDAC9 and cancer: Sall4 is associated with recurrence and metastasis in several type of cancers, including breast cancer [42], and its suppressive action on target genes prevents cell differentiation and maintains pluripotency by engaging an epigenetic repressor, such as Mi-2/NuRD, with histone deacetylase activity (HDAC) [43], DNA methyltransferases [44], as well as c-MYC and CCND1 down-stream targets of the Wnt/beta-catenin signaling pathway [45].