In biochemistry, a dual-specificity kinase (EC 2.7.12.1) is a kinase that can act as both tyrosine kinase and serine/threonine kinase. MEKs, involved in MAP pathways, are principal examples of dual-specificity kinases. Other common examples include: * ADK1 (Arabidopsis dual specificity kinase 1) * CLK1, CLK2, CLK3, * * DYRK1A, DYRK1B, DYRK2, DYRK3, * * TESK1, TESK2 * TTK The systematic name of this enzyme class is ATP:protein phosphotransferase (Ser/Thr- and Tyr-phosphorylating).