ERFE expression in CDAII patients and during erythroid differentiation in normal and SEC23B-deficient cells. (A) FAM132B messenger RNA (mRNA) levels (normalized to β-actin) in PBLs from 37 CDAII patients and 29 HCs. Overexpression of the FAM132B gene in CDAII patients (9.11 ± 0.10) compared with HCs (8.32 ± 0.12; P < .0001) was observed. Data are presented as mean ± standard error of the mean (SEM). P value by the Student t test. (B) Human protein ERFE evaluation in plasma samples from 29 CDAII patients and 12 HCs. Data are presented as mean ± SEM. P value by the Student t test. (C) FAM132B mRNA levels (normalized to β-actin) in PBLs from 37 CDAII, 21 BT-intermedia, 13 HS patients, and 29 HCs. Data are presented as mean ± SEM. **P < .0001; *P < .05 vs HC group (Student t test). (D) FAM132B mRNA levels (normalized to glyceraldehyde-3-phosphate dehydrogenase [GADPH]) in normal CD34⁺ cells induced to erythroid differentiation by EPO at 7, 9, 11, and 13 days. Data are presented as mean ± SEM of 3 experiments. P value by analysis of variance (ANOVA) test. (E) FAM132B mRNA levels (normalized to GADPH) in stable clones of K562 silenced for SEC23B at 2 and 5 days of erythroid differentiation by hemin. Data are presented as mean ± SEM of 3 experiments. *P < .05 (Student t test). (F) Immunoblot of ERFE protein in total cell lysate and medium samples from SEC23B-silenced K562 cells induced to erythroid differentiation at 2 and 5 days; GAPDH was loading control for total cell lysate, whereas medium samples were normalized by Ponceau red staining of the blots. Densitometric analysis of the blot showed on the left (5 days): ERFE protein levels of both SEC23B-silenced K562 clones were normalized on sh-CTR K562 clone.