XPR1 regulates iron-recycling macrophages in the spleen and BM. (A) Representative flow cytometry plots, frequencies, and numbers (mean ± SD) of splenic macrophages from E18.5 control (Xpr1^fl/fl and Xpr1^fl/+) and Vav1^iCreXpr1^fl/fl embryos (pre-gated on CD45⁺Lin⁻Ly6C⁻Ly6G⁻SiglecF⁻CD64⁺ cells). n = 3–10 per group, pooled from two independent experiments. Statistical analysis was performed using the Student’s t test. (B) Representative flow cytometry plots, frequencies, and numbers (mean ± SD) of splenic Ly6C^hi monocytes from E18.5 Xpr1^fl/fl and Vav1^iCreXpr1^fl/fl embryos (pre-gated on CD45⁺Lin⁻Mac⁻SiglecF⁻ cells). Data show n = 3–10 per group and are pooled from two independent experiments. Statistical analysis was performed using the Student’s t test. (C) Representative flow cytometry plots, frequencies, and numbers (mean ± SD) of splenic red pulp macrophages (RPMs) from adult Xpr1^fl/fl and Mrc1^CreXpr1^fl/fl mice (pre-gated on CD45⁺Lin⁻Ly6G⁻SiglecF⁻CD90⁻MHCII⁻ cells). Data show n = 3–5 per group and are pooled from two independent experiments. Statistical analysis was performed using the Student’s t test. (D) Representative flow cytometry plots, frequencies, and numbers (mean ± SD) of splenic Ly6C^hi monocytes from adult Xpr1^fl/fl and Mrc1^CreXpr1^fl/fl mice (pre-gated on CD45⁺Lin⁻Ly6G⁻SiglecF⁻CD90⁻B220⁻CX3CR1⁺CD64⁺ cells). Data show n = 3–5 per group and are pooled from two independent experiments. Statistical analysis was performed using the Student’s t test. (E) Representative flow cytometry plots, frequencies, and numbers (mean ± SD) of F4/80⁺MerTK⁺ BM macrophages (top) (pre-gated on CD45⁺Lin⁻Ly6C⁻Ly6G⁻) and among these, CD163⁺TIM4⁺ macrophages (bottom) from adult Xpr1^fl/fl and Mrc1^CreXpr1^fl/fl mice. Data show n = 4–6 per group and are pooled from two independent experiments. Statistical analysis was performed using the Student’s t test. (F) Representative flow cytometry plots, frequencies, and numbers (mean ± SD) of BM monocytes (CD115⁺CX3CR1⁺) from adult Xpr1^fl/fl and Mrc1^CreXpr1^fl/fl mice (pre-gated on CD45⁺Lin⁻ Ly6G⁻Ly6C⁺SiglecF⁻). Data show n = 4–6 per group and are pooled from two independent experiments. Statistical analysis was performed using the Student’s t test. ***P < 0.001 and ****P < 0.0001. ns, not significant.