Reply to 'Complexity of molecular crowding in cell-free enzymatic reaction networks'.

<p>In our paper published in 2013<sup><a href="http://www.nature.com/nnano/journal/v9/n6/full/nnano.2014.111.html#ref1">1</a></sup>, we reported on the influence of molecular crowding on gene-expression dynamics, specifically promoting the robustness of gene expression. We also established the first multiscale synthetic biology approach (single molecule <em>ex vivo</em> artificial cells) for the study of gene regulation using cells as natural guiding principles. Our paper demonstrates that the impact of molecular crowding on gene expression can be modulated by genetic components, a negative feedback loop and crowding composition.</p>