Figure 1.

Schematic illustration of the Janus kinase signal transducer and activator of transcription (JAK/STAT) signaling cascade. The activation of JAKs subsequent cytokine binding results in the phosphorylation of STATs, which dissociate from the receptor, followed by dimerization and translocation to the nucleus to induce the transcription of the target genes. In addition to STATs, JAKs interact with various adaptor proteins, triggering several signaling cascades such as mitogen-activated protein kinase (MAPK), phosphatidylinositol-3-kinase (PI3K), a serine/threonine-protein kinase (AKT), and mammalian target of rapamycin (mTOR), which ultimately regulate cell proliferation, differentiation, cell survival, and cell cycle progression.