a transcription factor that plays a role in the inducible expression of cytokine genes in T cells, especially in the induction of the IL-2 and IL-4. Also control gene expression in embryonic cardiac cells. Could regulate not only the activation and proliferation but also the differentiation and programmed death of lymphoid and nonlymphoid cells. Highly expressed in placenta, lung, kidney, testis and ovary. Weakly expressed in spleen and thymus. Not expressed in peripheral blood lymphocytes. 23 alternatively spliced isoforms of the human protein hve been reported. Note: This description may include information from UniProtKB.