HumanZyme was founded in 2005 to develop a line of authentic human recombinant proteins for various life science applications. Prior to 2005, commercially available “human” proteins were predominantly limited to protein molecules manufactured in E. coli, insect cells (Sf9), or alternative mammalian cells (CHO). Such non-human expression systems, while adept at producing large quantities of protein, often cannot make a native human protein. Only a human cell contains the machinery to properly facilitate the making of a protein’s authentic human structural aspects, such as glycosylation, cleavage of amino acid residues, disulfide bond formation, and folding into the proper 3-dimensional shape. Protein structure, in turn, confers chemical and biological properties such as resistance to proteases, binding affinities, isoelectric point, and biological activity. To gain access to the benefits of authentic human proteins, researchers had to produce and purify their own supply. This sort of expensive home brew production not only diverted attention from the laboratory’s core research goals but also lacked many of the attributes of an industrial production operation including quality control, batch to batch consistency, and scalability. After several years of technological development, HumanZyme succeeded in creating a process for quickly creating stable HEK293HS cell lines, each capable of expressing high levels of a specific, authentic, tag-free human protein. Furthermore, each cell line has been engineered to grow in suspension in serum-free, chemically defined cell culture media, providing a means to manufacture large quantities in bioreactors using a repeatable process.