Therapeutic recombinant proteins produced in mammalian expression systems might have folding issues and are confined in the endoplasmic reticulum by cellular quality control system, resulting in poor expression and yields. We have developed a novel technology called TAPBOOST technology, which controls protein folding and cellular quality control systems specifically for a targeted protein. A proprietary protein (TAPBOOST protein) is expressed together with a therapeutic protein (targeted protein), followed by the interaction between TAPBOOOST protein and the targeted protein, resulting in enhanced production of the targeted protein. TAPBOOST has successfully enhanced the production of many therapeutic recombinant proteins including monoclonal antibodies and Fc fusion proteins, and importantly, monoclonal antibodies produced by the technology retained the ability to bind to the corresponding epitope, and enzymes retained their biological activity. Intriguingly, the expression of hard-to-express proteins such as G protein-coupled receptor (GPCR) was also improved by the technology and GPCR protein expressed by the technology was strongly activated after the ligand binding. The unique mechanism of action enables this technology to combine with other existing expression technologies to enhance the production of therapeutic protein. To summarize: (1) TAPBOOST technology can enhance the production of targeted proteins by exploiting protein folding and cellular quality control systems, (2) TAPBOOST technology is more effective if the protein of interest is hard to produce, and (3) TAPBOOST technology is easily implemented into current bioprocess or expression system.