MAP kinase-interacting serine/threonine-protein kinase 2 is an enzyme encoded by the MKNK2 gene, which is a member of the calcium/calmodulin-dependent protein kinases (CAMK) Ser/Thr protein kinase family, belonging to the protein kinase superfamily. This protein is one of the downstream kinases activated by mitogen-activated protein (MAP) kinases. It phosphorylates the eukaryotic initiation factor 4E (eIF4E), thus playing important roles in the initiation of mRNA translation, oncogenic transformation and malignant cell proliferation. In addition to eIF4E, this protein also interacts with von Hippel-Lindau tumor suppressor (VHL), ring-box 1 (Rbx1) and Cullin2 (Cul2), which are all components of the CBC(VHL) ubiquitin ligase E3 complex. Multiple alternatively spliced transcript variants have been found, but the full-length nature and biological activity of only two variants are determined.