Biopharmaceuticals are produced mainly by Chinese hamster ovary (CHO) cell lines, for which advances in protein formats, bioprocesses, and bioprocess control are introducing novel challenges (1). Thus far, those challenges have been tackled either by technical innovations and media optimization or by advances in host-cell engineering (2, 3). Some technical innovations bring further challenges, such as those related to the compatibility of CHO cultures with highly automated bioprocesses and continuous high-density culture modes (4). With regard to host-cell engineering, most…