A novel peptide CXCR4-targeted-NIR fluorescence imaging agent (CXCR4-IR-783) was recently described to detect primary osteosarcoma and lung micro-metastasis22 although the authors are seeking improvements of the probe aimed to reduce the high signal-to-noise ratio and improve specificity toward neoplastic cells. The gene discussed is CXCR4; the disease is osteosarcoma.