Jak-Stat signaling pathway PW:0000209 The Jak-Stat pathway is a main intracellular cascade initiated primarily in response to cytokine and also other ligand signaling. Four Janus kinases (Jak) and seven signal transducers and activators of transcription (Stat) families of proteins mediate the action of almost 40 cytokine receptors, including the receptor for leptin. Combinations between four Jak(s) and seven Stat(s) shape the outcome of ligand- triggered signaling through the various receptors. pathway receptor signaling pathway via JAK-STAT signaling pathway pertinent to immunity tyrosine-specific protein kinase mediated signaling pathway