Tissue-specific expression of ATG4A in human erythropoiesis. (A) Fold change (log₂) in the expression of ATG genes in human basophilic erythroblasts relative to undifferentiated hematopoietic stem and progenitor cells (HSPCs). Data courtesy of Yan et al (GSE107218).²⁵  The data are plotted as mean ± SEM of 3 independent replicates. Significance was determined using an unpaired 2-tailed Student’s t test. *P < .05. (B) Scheme of ex vivo human erythroid differentiation of CB-derived CD34⁺ HSPCs. Erythroid culture: immature CD34⁺ HSPCs are cultured for 18 days in EDM containing the timed addition of cytokines to become reticulocytes. (C) Transcript levels of ATG4A relative to GAPDH on days 0, 5, 9, and 13 of erythroid culture. The data are plotted as mean ± SEM of 3 independent replicates. Significance was determined using a 1-way analysis of variance (ANOVA) followed by a Dunnett post-test. (D) Protein lysates were collected from erythroid culture on days 0, 5, 9, and 13 and analyzed using immunoblot analysis for ATG4A and GAPDH.