Although hdac1 and mbbd3a were also upregulated in the rb1/rb1 mutant (hdac1 1.3-fold, Padj=0.00123; mbd3a 1.2-fold, Padj=0.06262), neither was as highly elevated as rbbp4. qRT-PCR confirmed the change in gene expression for rbbp4 and hdac1 in rb1 tumor tissue (Fig. 4C) and in the 5 dpf rb1/rb1 mutant larvae (Fig. 4D). The gene discussed is HDAC1; the disease is neoplasm.