The investigation of the lenalidomide mechanism of action in other hematological malignancies, such as myelodysplastic syndrome with del5q, identified the next neosubstrate of CRBN; a casein kinase 1 α (CK1α; encoded on chromosome 5q by CSNK1A1) [9]. Here, CSNK1A1 is linked to myelodysplastic syndrome.