CXCR4 and lung cancer: Interleukin-24 (IL-24) is a membrane receptor-mediated tumor growth inhibitory factor that inhibits the expression of the transcription factor GLI1 in lung cancer cells by inhibiting the Akt-mTOR and SDF-1/CXCR4 signaling axes, thereby inducing DNA damage in lung cancer cells and leading to cell death [7].