Protein tags facilitate the development of bifunctional molecules.

Bifunctional molecules are a leading trend in drug development today, but the lack of small-molecule ligands greatly limits their development. Within this landscape, protein tags have played a pivotal role in advancing the field, enabling work from initial proof-of-concept validation to in-depth mechanistic research and further exploration of biological effects. In this review, we systematically summarize and analyze the various protein tags employed in the development of bifunctional molecules, aiming to help researchers in the field select suitable protein tags for their studies. Furthermore, we offer a perspective on the future application of protein tags in bifunctional molecule development.