STAT1 and Autoimmunity: These include an increase in tumor-infiltrating cells, decrease in circulating regulatory T cells, manifestations of autoimmunity and development of autoantibodies, changes in cytokine concentrations, modulation of signal transducer and activator of transcription (STAT) 1/STAT3 balance in tumor cells and host lymphocytes, and normalization of T cell STAT1 signaling defects in peripheral blood lymphocytes [26].