HDAC9 and cancer: Recent studies have shown the evidence of HDAC mediated SOCS3 expression regulation: HDACi treatment can promote the SOCS1 and SOCS3 expression in human colorectal cancer and human leukemia through inducing the hyperacetylation of histones associated with the SOCS3 promoters [37, 38], which further suppress Janus kinase/signal transducers and activators of transcription (JAK/STAT) signaling involved in the oncogenesis of different cancers [39].