ESPL1 and myelodysplastic syndrome: In order to investigate whether the drugs azacitidine, lenalidomide and rigosertib, all commonly used in MDS treatment, are able to modulate the SAD value, i.e. the occurrence of bone marrow cells with prominent separase activity in vivo, we performed cell culture experiments on MDS-L cells, a human myeloid cell line best suitable as an in vitro model system of MDS [32].