Important transcription factor regulating the expression of genes involved in immune and inflammatory responses. Binds to regulatory regions of several acute-phase and cytokines genes and probably plays a role in the regulation of acute-phase reaction, inflammation and hemopoiesis. The consensus recognition site is 5'-T[TG]NNGNAA[TG]-3'. Plays an important role in adipose tissue differentiation. Regulates the transcriptional induction of peroxisome proliferator-activated receptor gamma (PPARG) as well as other adipogenesis key player genes. Isoform 3:acts as a dominant negative through heterodimerization with isoform 2.