Difficult to express proteins represent an increasing amount of therapeutic molecules. Considerable optimization is often required for downstream applications such as assay development and functional characterization. 

Cell-free systems emerged as powerful tools for the synthesis of structurally and functionally divergent enzymes, antibodies and membrane proteins.

Vesicle-based eukaryotic cell-free systems enable co-translational protein translocation and posttranslational modifications. 

Hence, these systems provide a multitude of options for detailed protein studies.