“…Considering that JAK-STAT signal transduction is initiated by the binding of ligands, such as cytokines to their receptors, proper JAK activity in the JAK-STAT pathway is a key element to orchestrate the immune response, and dysfunctional JAKs are directly responsible for cancers, immune system-related diseases, and autoimmune disorders [ 96 ]. These enzymes, referred to as Janus kinases or simply JAK kinases, are an essential element for the transmission of cytokine signals for such important cytokines as IL-2, IL-4, IL-7, IL-9, IL-15, and IL-21, which transmit their signals via gamma chain receptors (γc) [ 97 ], since GM-CSF, IL-3, and IL-5 signalling is via the beta type of receptor [ 98 ]. Another class of receptor is the heterodimer composed of the gp 130 protein (or its homologue), which is responsible for signalling from IL- 6, IL-11, IL-31, IL-35, and IL-27 [ 99 ].…”