Eukaryotic translation initiation factor 4 gamma 3 is a protein that in humans is encoded by the EIF4G3gene. The gene encodes a protein that functions in translation by aiding the assembly of the ribosome onto the messenger RNA template. Confusingly, this protein is usually referred to as eIF4GII, as although EIF4G3 is the third gene that is similar to eukaryotic translation initiation factor 4 gamma, the second isoformEIF4G2 is not an active translation initiation factor.