JAK2 and acute myeloid leukemia: However, of the eleven novel synthetic N-heterocyclic macrocyclic derivatives tested (Figure 6) only compound 60 possessed multi-targeting potential against HDAC (87 nM), transmembrane ligand-activated receptor tyrosine kinase (FLT3) (87 nM), and Janus kinase 2 (JAK2) (0.68 μM), with a high cytotoxic effect on human acute myeloid leukemia cell line MV4-11 and human erythroleukemia (HEL) cells.