Figure 1.

Function and target of JAK kinases. Schematic representation of relevant Janus kinases (JAK) - signal transducers and activators of transcription (STAT) signaling pathways potentially involved in the pathogenesis of spondyloarthritides. Binding of the different Interleukins (IL) to their specific receptor subunits on different cell populations, eg T cells, innate lymphoid cells (ILC) or effector cells such as osteoblasts, fibroblasts or keratinocytes leads to activation of JAK-STAT pathways. The different isoforms of JAK are coupled to specific receptor/cytokine pairs and allow for a targeted inhibition with a specific JAK inhibitor. Adapted with permission from Hammitzsch A, Lorenz G, Moog P. Impact of Janus Kinase Inhibition on the Treatment of Axial Spondyloarthropathies. Front Immunol. 2020;11:591176.49