JAK1 and acute myeloid leukemia: Broad kinase inhibition screens documented its ability to inhibit kinases known to support proliferation of AML cells including SYK (IC50 = 2.9 nmol/L), WT and mutant forms of FLT3 (IC50 = 1.0–1.8 nmol/L), KIT-MUT (IC50 = 3.5–3.6 nmol/L), TAK1 (IC50 = 7 nmol/L), JAK1(IC50 = 2.9 nmol/L), JAK2 (IC50 = 6.3 nmol/L), RET, KDR, NTRK2, CLK2, LYN B, MLK1, and RSK-2 (IC50 = 9.7 nmol/L; Fig. 1B).