The CX3CR1 receptor for CX3CL1 is expressed on immune cells. CX3CR1 expression was assessed on leukocytes isolated from the spleens of naïve mice that express GFP driven by the CX3CR1 promoter (CX3CR1-GFP/GFP mice). Cells were stained with antibodies against CD4, CD8, B220 (B cells), CX11b, F480 (macrophages), and CD49b (NK cells) and analyzed via flow cytometry. The antibody positive gated populations are displayed as histograms with the percentage of CX3CR1 expressing cells within that population noted above each histogram subgate. These results are representative of two separate experiments (n = 4 mice).