Transcriptional regulator mainly expressed in hematopoietic cells that plays a critical role in cellular growth, differentiation and immune response .Plays a key role in the differentiation of T-helper 1 cells and the production of interferon-gamma.Participates also in multiple neutrophil functions including chemotaxis and production of the neutrophil extracellular traps (By similarity).After IL12 binding to its receptor IL12RB2, STAT4 interacts with the intracellular domain of IL12RB2 and becomes tyrosine phosphorylated.