Trib1 expression increases with eosinophil commitment and is required for EoP homeostasis. (A) Model of eosinophil and neutrophil development from the HSC including the EoP. (B) Trib1 expression in sorted CMP, GMP, and EoP from WT C57BL/6 mice relative to 18s, normalized to Trib1^+/+ neutrophils; representative of 3 experiments. (C) Relative expression of TRIB1 in human CMP and eosinophils (obtained from the differentiation map data set²⁰ ) using BloodSpot.⁶⁵  (D) qPCR from Trib1^+/+ and Trib1^ΔHSC whole BM assayed for Trib1 expression relative to 18s, normalized to Trib1^+/+ BM; representative of 3 experiments. (E) Representative plots of BM EoP, gated on live, lineage⁻CD34⁺ cells. Frequency of live cells (F) and absolute number (G) of BM EoP; n = 4 mice per group, representative of 2 experiments. *P = .0131; **P = .0013; ****P < .0001; unpaired Student t test. Frequencies and error bars are mean ± standard error of the mean (SEM) of live cells.