Gene cluster II represents genes that were mostly overexpressedin a subgroup of tumors (B) and include RB1, NCOR2, HDAC6,HDAC10, HDAC3, HDAC7 and HDAC1. In this cluster,HDAC1 was the only gene that was induced in almost all tumor samples,suggesting that HDAC1 play an important role in brain tumorigenesis(Figure 2A). The gene discussed is RB1; the disease is neoplasm.