For analysis of HDAC expression in human NB, a collection of Gene Expression Omnibus (GEO) clinical NB samples containing RNA-sequencing data from 498 primary tumors was appraised for HDAC expression in subgroups of NB, in part to assess which NB patient subpopulations may most benefit from HDAC inhibitor therapy. The gene discussed is HDAC9; the disease is neuroblastoma.