 Interaction between these two eukaryotic initiation factors (eIFs) of the eIF4F complex is necessary for 40S ribosomal subunit recruitment to the 5' end of mRNAs, which is further thought to occur with mRNA 5'cap to 3' poly(A) tail loop formation.The virus may even use partially-cleaved eIF4G to aid in initiation of IRES-mediated translation.Cells may also use IRESs to increase translation of certain proteins during mitosis and programmed cell death.