The potential of CK1δ/ε-specific and CK1α-specific inhibitors in leukemia, lymphoma and myeloma therapy is better described, and will be discussed below, including the rationale for targeting CK1δ/ε in B cell lymphomas and CK1α in myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). The gene discussed is CSNK1A1; the disease is myelodysplastic syndrome.