A degrading game plan for cancer therapy Certain classes of proteins that contribute to cancer development are challenging to target therapeutically. Winter et al. devised a chemical strategy that, in principle, permits the selective degradation of any protein of interest. The strategy involves chemically attaching a ligand known to bind the desired protein to another molecule that hijacks an enzyme whose function is to direct proteins to the cell's protein degradation machinery. In a proof-of-concept study, they demonstrated selective degradation of a transcriptional coactivator called bromodomain-containing protein 4 and delayed the progression of leukemia in mice. Science , this issue p. 1376