Figure 1.

Signal transducer and activator of transcription 3 (STAT3) activation: STAT3 activation is initiated by binding of the ligand, interleukin 6 (IL-6), to its receptor, which consists of glycoprotein 80 kDA and glycoprotein 130 kDA (gp130). Binding of IL-6 to the receptors leads to dimerization of the cytoplasmic domain of the gp130 peptide, with subsequent activation of associated Janus tyrosine kinases, notably Janus kinase 2 (JAK2). The activated JAKs in turn phosphorylate STAT3, which allows for dimerization of STAT3. The STAT3 dimer then translocates to the nucleus where it regulates transcription.

Abbreviations: α, alpha; IL-6R, interleukin-6 receptor.