Represses translation by preventing reactivation of elongation factor eEF1A (By similarity). May also inhibit nuclear import by competing with nuclear import substrates for binding to a subset of nuclear transport receptors (PubMed:15282309). Has additionally been proposed to act as a redox sensor involved in cellular oxidative stress surveillance (PubMed:18519672). {ECO:0000250|UniProtKB:B0BNF8, ECO:0000269|PubMed:15282309, ECO:0000269|PubMed:18519672}. This is the function of HTATIP2 (HIV-1 Tat interactive protein 2, Ensembl gene identifier ENSG00000109854).