A nucleated, immature erythrocyte in which the nucleus occupies a relatively smaller part of the cell than in its precursor, the basophilic erythroblast. The cytoplasm is beginning to acquire hemoglobin and thus is no longer a purely basophilic, but takes on acidophilic aspects, which becomes progressively more marked as the cell matures. The chromatin of the nucleus is arranged in coarse, deeply staining clumps. This cell is CD71-positive and lacks hematopoeitic lineage markers. [ http://openisbn.com/search.php?q=0721601464&isbn=1/ ]