RET is the medical term for reticulocytes. Reticulocytes are red blood cells that have lost their nuclei, but are not fully mature. Because the nucleus has just been removed, but there are still many organelles in the cytoplasm, these organelles are stained to give a reticulocytic appearance, so they are called reticulocytes. The reticulocyte examination can reflect the hematopoietic function of the bone marrow. When the hematopoietic function of bone marrow is normal, the number of reticulocytes is normal; when the hematopoietic function of bone marrow fails, the number of reticulocytes decreases. In addition, when there is acute blood loss or hemolysis in the body, the number of reticulocytes increases significantly, which is a compensatory reaction that occurs in the bone marrow to replenish the reduced red blood cells in the blood by releasing immature, newly denucleated red blood cells.