To determine CXCR4 expression on mononuclear cells expressing pan-cytokeratin, we measured human cytokeratin 14, 15, 16, and 19 (pan-cytokeratin) along with CXCR4 on peripheral blood mononuclear cells (PBMC) by FACS in 16 NSCLC patients and 10 normal controls. The gene discussed is CXCR4; the disease is non-small cell lung carcinoma.