Overexpression of JUN and FOS is a usual and early event in lung cancer,which results from the signalization of ecto-multiplication.Signal transducers and activators of transcription are factors of cellular proliferation and apoptosis inhibition,which mediate cytokine signaling.These transcription factors are key regulators of signal transduction and transcriptional control of cytokines,hormones and growth factors and participate in cellular proliferation and differentiation.It provokes oncogene activation and expression of JUN and FOS by phosphorylation,and then activates JUN and FOS to form heterodimers or JUN homodimer,combines with activator protein-1 promotor binding site,induces oncogene expression and participates in cell malignant transformation.