Cup is an eIF4E binding protein required for both the translational repression of oskar and the recruitment of Barentsz.

Wilhelm JE, Hilton M, Amos Q, Henzel WJ. "Cup is an eIF4E binding protein required for both the translational repression of oskar and the recruitment of Barentsz." J. Cell Biol.. 2003;163(6):1197-204.