Knockdown of TET2 led to the generation of marker CFU-E cells. (A) TET2-knockdown CFU-E cells were cultured for 13 days, and the GPA⁻ population was sorted. (B) Representative cytospin images of sorted luciferase CFU-E and TET2-knockdown GPA⁻ cells. (C) Flow cytometry analysis of luciferase CFU-E and TET2-knockdown GPA⁻ cells using the surface markers IL-3R, GPA, CD34, CD36, and CD71. (D) Proliferation of luciferase CFU-E and TET2-knockdown GPA⁻ cells in the presence of EPO only or EPO plus SCF. (E-F) Differentiation of luciferase CFU-E and TET2-knockdown GPA⁻ cells. Sorted luciferase and TET2-knockdown GPA⁻ cells were cultured for 5 or 15 days. Expression of GPA (E) or band 3/α4 integrin (F) was examined by flow cytometry analysis. (G) Quantitative analysis of results shown in panel F from 3 independent experiments. (H) Representative cytospin images of erythroblasts. (I) Western blot analysis of c-Kit, p–c-Kit, AKT, p-AKT, ERK, p-ERK, and SHP-1. GAPDH was used as loading control. (J) Quantitative analysis of results shown in panel H from 3 independent experiments. *P < .05, **P < .01, ***P < .001.