The STAT family of proteins in cytokine signaling.

It has now been well established that the STAT family of proteins play important roles in cytokine-mediated specific gene activation. Although significant progress has been made toward the understanding of the structure and function of STATs as well as the regulation of STAT signaling pathways, many important questions remain to be answered. STAT PTPase(s) and STAT serine kinase(s) which play important roles in regulating STAT activity have not been identified. In addition, the molecular mechanisms of the negative regulation of STAT signaling by recently discovered protein inhibitors and the crosstalk between STAT and other signal transduction pathways have not been understood. The JAK/STAT field remains to be challenging and exciting.