Inhibitor of DNA Binding Protein 3 (ID3)

ID3 gene was localized to the neuroblastoma consensus deletion region, 1p36.2-p36.12. Its predicted protein was 95.8% identical to the mouse HLH462 protein and had clear homology to the mouse Id and Drosophila emc proteins. The gene was expressed at high abundance in adult lung, kidney, and adrenal medulla, but not in adult brain. Despite prominent HEIR1 expression in adrenal medulla, which is a prime target for neuroblastomas, 10 of 12 neuroblastoma-derived cell lines showed very low levels of HEIR1 mRNA. Low HEIR1 expression was generally found in tumor cell lines with NMYC overexpression, whereas the 2 cell lines displaying high HEIR1 levels did not overexpress NMYC.