A cyclic peptide inhibitor of CXCR4 (peptide R), designed as an SDF‐1 mimetic peptide, and already validated to inhibit CXCR4 downstream pathways and to exert anti‐metastatic effects, was utilized to better explain the role of CXCR4 inhibition in the modulation of lung cancer metastatic potential [27, 28]. The gene discussed is CXCR4; the disease is lung cancer.