Chromatin-interacting protein that forms a stable heterodimer with interleukin enhancer-binding factor 3/ILF3 and plays a role in several biological processes including transcription, innate immunity or cell growth (PubMed:18458058, PubMed:31212927). Essential for the efficient reshuttling of ILF3 (isoform 1 and isoform 2) into the nucleus. Together with ILF3, forms an RNA-binding complex that is required for mitotic progression and cytokinesis by regulating the expression of a cluster of mitotic genes. Mechanistically, competes with STAU1/STAU2-mediated mRNA decay (PubMed:32433969). Also plays a role in the inhibition of various viruses including Japanese encephalitis virus or enterovirus 71. {ECO:0000269|PubMed:10574923, ECO:0000269|PubMed:11739746, ECO:0000269|PubMed:18458058, ECO:0000269|PubMed:21123651, ECO:0000269|PubMed:31212927, ECO:0000269|PubMed:32433969, ECO:0000269|PubMed:9442054}. (Microbial infection) Plays a positive role in HIV-1 virus production by binding to and thereby stabilizing HIV-1 RNA, together with ILF3. . This is the function of Ensembl gene identifier ENSG00000143621 (ILF2, interleukin enhancer binding factor 2).