Cell-line development traditionally has focused on genetic engineering of chromosomal DNA in cellular nuclei. Combining technological advances such as zinc-finger nucleases (ZFNs) and transcription activator-like effector nucleases (TALENs) with ever-increasing genomic knowledge has enabled scientists to get impressive performance from microbial, plant, and animal cells. But few researchers have considered the potential for manipulating how genes are transcribed as an avenue for increasing productivity — until recently, that is. Niall Barron is a professor of biochemical engineering at Ireland’s National…