Erythroblasts and Myelocytes

"Let me become a great red blood cell one day" - This is the story of Red Blood Cell before she became Red Blood Cell, when she was a young Erythroblast. The Erythroblasts are training hard to become full-fledged Red Blood Cells under the supervision of their teacher, Macrophage, but Erythroblast is directionally-challenged, and she's always getting lost in the middle of drills. One day, while practicing to evacuate from bacteria, Erythroblast once again loses her way.