Tet2 mutations increase circulating myeloid cells of old WT but not TNF^–/– recipient mice. Circulating myeloid immune populations were compared in young WT, old WT, and old TNF^–/– recipient mice. (A-C) Total counts of circulating monocytes (A), Ly6C^high monocytes (B), and neutrophils (C). (D-F) Total circulating monocytes, neutrophils, and Ly6C^high monocytes as a proportion of total leukocytes (CD45⁺) cells, respectively. (G) Surface expression of F4/80 on Ly6C^high monocyte. (H) Intracellular expression of TNF in monocytes after stimulation with lipopolysaccharides. Data are shown as a stacked bar plot, in which orange represents gated CD45.2 Tet2^–/– cells and blue represents CD45.1 WT cells. Statistical significance determined by 2-way ANOVA with Tukey multiple comparisons test. Letters in the orange and blue columns denote significant differences (P ≤ .05) in the group means of CD45.2 or CD45.1 alleles, respectively. For all variables with the same letter, the difference between the means is significantly different. If 2 variables have different letters or no letters, they are not significantly different. Black bars with asterisks denote group differences, inclusive of both CD45.1 and CD45.2 alleles. ∗P ≤ .05; ∗∗P ≤ .01; ∗∗∗P ≤ .001; ∗∗∗∗P ≤ .0001.