Using ATP kinase assays, the IC50 values for CYT387 are a follows - JAK1 (11nM), JAK2, (18nM), JAK2 V617F (23nM) JAK3 (155nM), and TYK2 (17nM). In testing kinase arrays, CYT387 also had activity (defined as an IC50 < 100nM) detected against CDK2/cyclin A