FAM3D (family with sequence similarity 3, member D) deficiency reduces neutrophil recruitment to the aortic wall during abdominal aortic aneurysm (AAA) formation. A, Quantification of neutrophils in the infrarenal abdominal aortas of elastase-treated wild-type (WT) and FAM3D−/− mice at 0 day (WT, n=6; FAM3D−/−, n=6), 3 days (WT, n=7; FAM3D−/−, n=7), 7 days (WT, n=7; FAM3D−/−, n=6), and 14 days (WT, n=9; FAM3D−/−, n=7). Two-way analysis of variance (ANOVA) followed by Tukey’s test for multiple comparisons, *P<0.05, ns, no significance. B, Quantification of neutrophils in the peripheral blood of elastase-induced WT and FAM3D−/− mice at 0 day (WT, n=6; FAM3D−/−, n=6), 3 days (WT, n=7; FAM3D−/−, n=7), 7 days (WT, n=7; FAM3D−/−, n=6), and 14 days (WT, n=9; FAM3D−/−, n=7). Two-way ANOVA followed by Tukey’s test for multiple comparisons, *P<0.05. C, Quantification of Ly6Chigh monocytes in the infrarenal abdominal aortas of elastase-treated WT and FAM3D−/− mice at 0 day (WT, n=6; FAM3D−/−, n=6), 3 days (WT, n=7; FAM3D−/−, n=7), 7 days (WT, n=7; FAM3D−/−, n=7), and 14 days (WT, n=7; FAM3D−/−, n=7). Two-way ANOVA followed by Tukey’s test for multiple comparisons, *P<0.05, ns, no significance. D, Quantification of macrophages in infrarenal abdominal aortas of elastase-treated WT and FAM3D−/− mice at 0 day (WT, n=6; FAM3D−/−, n=6), 7 days (WT, n=7; FAM3D−/−, n=6), and 14 days (WT, n=9; FAM3D-/-, n=7). Two-way ANOVA followed by Tukey’s test for multiple comparisons, *P<0.05, ns, no significance. E, Representative immunohistochemical staining and quantification of neutrophil infiltration in infrarenal abdominal aortas of WT and FAM3D−/− mice 7 days after elastase induction, using the neutrophil-specific antibody Ly6G. Rat IgG was applied as a negative control. WT, n=8; FAM3D−/−, n=7. Scale bar, 20 μm. Mann-Whitney test, *P<0.05.