Transcriptional control is in part regulated by interactions between DNA-bound transcription factors, such as Egr-1/NGFI-A, and coregulatory proteins, such as NAB (for NGFI-A-binding proteins). The evolutionarily conserved NAB proteins, NAB1 and NAB2 are corepressors of EGF-1/NGFI-A. Both NAB1 and NAB2 contain an amino terminal NAB conserved domain 1 (NCB1), which is required for binding NGFI-A, and a carboxy terminal NCD2 domain, which is responsible for the repressor function of NAB proteins. NAB2 is principally localized in the nucleus and may play a role in the downregulation of NGFI-A activity as well as in controlling fundamental processes such as cell division, differentiation and apoptosis. NAB2 localizes to chromosome 12q13.3-14.1, a region that is rearranged in several solid tumors, lipomas, and liposarcomas.