(A–D) Cx3cr1^+/GFP and Cx3cr1^GFP/GFP mice were left untreated or administered normal saline (n = 5 per group). At 7 days thereafter, omental tissues were evaluated for CD45 staining (A), numbers of CD11b^intF4/80^loMHCII⁺ (SPM-like) cells (B), CD31 staining (C), and microvessel density (D). Scale bar in A and C: 200 μm. (E) CX3CR1⁺ SPM-like cells were sorted from omenta of untreated C57BL/6 mice and at day 1 following saline administration (n = 5 per group). Lysates of pooled cells of each group were screened on antibody arrays. Shown are proteins with > 1.5-fold higher levels in saline-treated mice relative to untreated mice. Bars represent the averages of 2 replicates. Asterisks indicate proangiogenic proteins. (F and G) CX3CR1⁺ SPM-like cells were sorted from omenta of untreated C57BL/6 mice and at 1 hour following saline administration (n = 6 per group) and were stained for NF-κB p65. (F) Representative images of cells. Scale bar: 20 μm. (G) Percentages of cells with nuclear NF-κB p65. For each mouse, a minimum of 300 cells were evaluated. (H and I) Cx3cr1^+/GFP and Cx3cr1^GFP/GFP mice were left untreated or administered saline (n = 6 per group). At 7 days thereafter, all groups were inoculated i.p. with ID8 cells that express red fluorescent protein (RFP). Omental colonization was evaluated at 7 days following inoculation. (H) Representative images of tissues. Scale bar: 200 μm. (I) Tumor foci, expressed as the percentage of area within each tissue. For each mouse, RFP fluorescence was evaluated in 3–5 random and independent 40× microscopic fields. Age-matched adult female mice were used in A–I. **P < 0.01, ***P < 0.001, ****P < 0.0001, by Tukey’s multiple comparisons test in B, D, and I, by unpaired 2-tailed Student’s t-test in G.