5-Iodotubercidin (NSC 113939), an ATP mimetic, is a potent adenosine kinase inhibitor with an IC50 of 26 nM. 5-Iodotubercidin (NSC 113939) initiates glycogen synthesis in isolated hepatocytes by causing inactivation of phosphorylase and activation of glycogen synthase. 5-Iodotubercidin (NSC 113939) also inhibits CK1, insulin receptor tyrosine kinase, phosphorylase kinase, PKA, CK2, PKC and Haspin[1][2][3].