Two major new papers are now out from our lab’s collaborations with Guy-Bart Stan on the key issue of gene expression costs in bacteria. Both build on our 2015 paper on burden and were recently covered in an Imperial College London news article.Firstly, published in Nature Methods is an RNAseq study on the immediate effects of burden in E. coli. This study led to the creation of a general and tunable dCas9-based feedback controller to automatically control expression levels to tolerable amounts for cell growth. This work was led by Francesca Ceroni during her time with our group, with key contributions from our student Alice Boo and from Simone Furini in Italy and Tom Gorochowski from Bristol.Olivier Borkowski from our group was also involved in that paper, but additionally has his own work on burden now published in Nature Communications. In this paper, cell lysate technology is used to measure the burden of making a protein and this data feeds a model to predict how expressing it would decrease the growth of E. coli. This can even be used to predict multigene and operon expression burden, and we hope will become a widely-used approach.Both Francesca and Olivier have now moved to their own junior research fellow positions, with Francesca based at Chemical Engineering at Imperial and Olivier returning to Paris to join Genopole.