Serine/threonine-protein kinase that phosphorylates SFPQ/PSF, HNRNPA1 and EIF4E. May play a role in the response to environmental stress and cytokines. Appears to regulate translation by phosphorylating EIF4E, thus increasing the affinity of this protein for the 7-methylguanosine-containing mRNA cap. Required for mediating PP2A- inhibition-induced EIF4E phosphorylation. Triggers EIF4E shuttling from cytoplasm to nucleus. Isoform 1 displays a high basal kinase activity, but isoform 2 exhibits a very low kinase activity. Acts as a mediator of the suppressive effects of IFNgamma on hematopoiesis. Negative regulator for signals that control generation of arsenic trioxide As(2)O(3)-dependent apoptosis and anti-leukemic responses. Involved in anti-apoptotic signaling in response to serum withdrawal. {ECO:0000269|PubMed:11154262, ECO:0000269|PubMed:11463832, ECO:0000269|PubMed:12897141, ECO:0000269|PubMed:16111636, ECO:0000269|PubMed:17965020, ECO:0000269|PubMed:18299328, ECO:0000269|PubMed:20823271, ECO:0000269|PubMed:20927323, ECO:0000269|PubMed:21149447}. This is the function of ENSG00000099875 (MKNK2, MAPK interacting serine/threonine kinase 2).