The miRNA-l44/-451 locus, which is critical for erythroid homeostasis under stress conditions, is a key downstream effector of GATA-1, and the dysregulation of the miRNA-144/-451 complex triggers a mild form of anemia [13,30,32] Severity of anemia in SCD is associated only with miRNA-144, even though it is part of a polycistronic precursor with miRNA-451. The gene discussed is GATA1; the disease is anemia (phenotype).