The STAT4 gene is located on chromosome 2q32.2-q32.3. The STA4 gene encodes a homonymous protein STAT4, a member of the STAT family . This family consists of transcription factors. STA4 is essential for mediating responses to IL12 in lymphocytes and regulating the differentiation of T helper cells.
STAT family members are phosphorylated in response to cytokines and growth factors by receptor-associated kinases and then form homo- or heterodimers that translocate to the nucleus where they act as transcriptional activators.
Mutations in this gene may be associated with numerous autoimmune diseases (see STAT4 below). Alternative splicing results in multiple transcript variants encoding the same protein. An important paralog of this gene is STAT1.