HDAC9 and neuroblastoma: In addition to the standard treatment options, targeted therapies using inhibitors of molecules implicated in the pathogenesis of NB such as anaplastic lymphoma kinase (ALK), tropomyosin receptor kinase (TRK), the phosphatidylinositol 3′-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) and the insulin-like growth factor 1 receptor (IGF1R), histone deacetylases (HDAC) and others are in phase I/II clinical trials either alone or in combination [5–10] to improve the outcome of high-risk NB patients.