HDAC9 and neuroblastoma: In an attempt to capitalize on this useful information, a group of researchers led by Romanelli et al. designed a first-in-class dual EZH2/HDAC inhibitor (93) (Fig. 15) that displayed a balanced inhibitory potential towards both the targets and also inhibited the proliferation of U937, THP1 (hematological malignancies) RH4 (rhabdomyosarcoma), SH-N-SK (neuroblastoma) and U87 (glioblastoma) cancer cell lines.