Lentiviral and retroviral ProteoTuner systems make it possible to investigate the function of a specific protein of interest directly—by rapidly changing the abundance of the protein itself. These systems utilize a ligand-dependent destabilization domain (DD), and the ligand Shield1 to reversibly stabilize and destabilize a DD-tagged protein of interest in a predictable and dose-dependent manner. Your protein of interest is fused to a DD tag and rapidly stabilized by adding the Shield1 ligand to the culture medium. Plasmid formats are also available.