Eukaryotic Translation Initiation Factor 4E-Binding Protein 1 (4EBP1) is a number of the eIF4E-binding protein family. 4EBP1 regulates eIF4E activity by preventing its assembly into the eIF4F complex. 4EBP1 mediates the regulation of protein translation by hormones, growth factors and other stimuli that signal through the MAP kinase and mTORC1 pathways. Non-phosphorylated 4EBP1 competes with EIF4G1/EIF4G3 to interact with EIF4E. 4EBP1 is phosphorylated in response to various signals including insulin signaling, resulting in its dissociation from eIF4E and activation of mRNA translation. 4EBP1 has a role in progression of breast neoplasms through cell signaling.