While the role of biologics in treating human diseases has evolved dramatically over the past decade, so has genetic engineering. Rational genetic engineering to enhance biotherapeutic proteins has become a reality catalyzed by publication of the genome sequences of multiple Chinese hamster ovary (CHO) cell lines. Novel “designer” CHO cells modulate posttranslational modifications (PTMs) of recombinant proteins by genome editing, and it is now possible to knock-in or knock-out genes of yeast and mammalian cells precisely (within one DNA base…