Acts as a transcriptional repressor for zinc finger transcription factors EGR1 and EGR2. Homomultimers may associate with EGR1 bound to DNA. Isoform Short is found in myeloid leukemia cell line KG-1. The NAB conserved domain 1 (NCD1) interacts with EGR1 inhibitory domain and mediates multimerization. The NAB conserved domain 2 (NCD2) is necessary for transcriptional repression. Belongs to the NAB family.