MiR-223 acts as “a fine-tuner” of granulocytic differentiation and maturation [7] and promotes granulocytic differentiation in acute promyelocytic leukemia (APL) cells treated with retinoic acid (RA) which can induce up-regulation of C/EBPα (CCAAT-enhancer-binding proteins α). The gene discussed is CEBPA; the disease is acute promyelocytic leukemia.