Molecular studies revealed that haploinsufficiency of several genes (particularly RPS14, CSNK1A1, EGR1, miR-145, and miR-14a) located in 5q CDR contribute to the pathogenesis and hematological phenotype associated with MDS-5q [27,28,29]. The gene discussed is CSNK1A1; the disease is myelodysplastic syndrome.