Hanna et al. showed in different murine metastatic tumor models that, up to 24 h after intravenous cancer cell injection, PMos are recruited to premetastatic lung capillaries through the CX3CL1/CX3CR1 axis and engulf tumor material, while as early as 4 h after injection they interact with tumor cells in circulation and hamper their attachment to the lung microvasculature. This evidence concerns the gene CX3CR1 and neoplasm.