[STAT1: a many-sided transcription factor].

Cell homeostasis is regulated by numerous signaling proteins. Their main task is to process extracellular signals and activate the intracellular cascades of reactions that lead to the modulation of gene activity. One of the important signaling systems is the STAT family, which is comprised of seven members. Various STATs operate as effective transcription factors delivering cytokine and growth factor signals to the nucleus. The first found and most studied member of this family is STAT1. This review summarizes modern data on the role of STAT1 in the maintenance of cellular homeostasis, and special attention is paid to this protein in the proliferation and apoptosis of immune system cell processes. It is shown that disturbances in the functionality of this molecule might contribute to oncogenesis.