The ubiquitously expressed molecule Signal transducer and activator of transcription 6 (STAT6) is one of the key factors mediating the differentiation of T helper cells of type 2 (Th2) of the immune system, which are strongly associated with the development and maintenance of allergic diseases. The theoretical part of the present work sums up the current knowledge about STAT6 and reviews in detail the literature currently existing on this subject. In the practical part of this work, three original studies are presented, which demonstrate the identification of two novel target genes of STAT6, CC chemokine ligand 17/thymus activated and regulated chemokine (CCL17/TARC) and Suppressor of cytokine signaling-1 (SOCS-1), and explore the signal transduction components necessary to achieve full STAT6 activation.