Janus kinase 2/signal transducer and activator of transcription 3 pathway (JAK2/STAT3 pathway)

The **Janus kinase 2/signal transducer and activator of transcription 3 pathway** is a specific branch of the broader JAK/STAT signaling cascade. This intracellular signal transduction route involves the activation of **Janus kinase 2 (JAK2)**, a non-receptor tyrosine kinase, which phosphorylates and activates **signal transducer and activator of transcription 3 (STAT3)**. Upon activation by cytokines or growth factors binding to cell surface receptors, JAK2 phosphorylates STAT3; STAT3 then dimerizes and moves to the nucleus where it regulates gene expression involved in cell proliferation, survival, differentiation, immune function, inflammation, apoptosis resistance, tumorigenesis, neuroprotection/neuroplasticity[1][8][9]. This pathway is implicated in numerous diseases—most notably various cancers due to its role in promoting cell survival/proliferation—and inflammatory conditions[1][6]. Drugs such as ruxolitinib target this axis by inhibiting the enzymatic activity of JAK kinases. **Note:** The entry "Janus kinase 2/signal transducer and activator of transcription 3 pathway" refers to a *signaling pathway*, not a single molecular target. For structured data purposes it is more accurate to split this into its two main components—**Janus kinase 2 (JAK2)** [enzyme] and **signal transducer and activator of transcription 3 (STAT3)** [transcription factor]—each with their own canonical names. The current form combines two distinct proteins plus their functional relationship; thus `is_incorrect` should be marked as true for use as an individual drug target entry[1][4].

Other names

JAK2-STAT3 signalingJAK2/STAT3 axisJanus kinase 2–signal transducer and activator of transcription 3 signaling pathway

Inhibition of tyrosine kinase activity (for drugs targeting JAK2)