Mammalian cell lines are preferred in bioprocessing due to their ability to generate sizable and complex proteins that can perform post-translational modifications that are similar to those made in humans. Additionally, proteins in these cell lines are able to be secreted instead of having to go through cell lysis to extract with protein refolding such as in bacteria. Proper protein folding post-translational modifications are vital to maintain the quality of target molecules. Mammalian cell cultures are also used for expressing recombinant proteins and provide functions such as developing vaccines. They are able to produce molecules such as mAbs (e.g. murine myelomas), and therapeutic proteins; mammalian cells are able to produce high-quality proteins which are similar to their biochemical characteristics of that in humans.