Modifications to messenger RNA (mRNA) molecules can influence the extent to which a given gene is expressed. For example, microRNA molecules, which are found in miRISC complexes (red), can bind to the mRNA molecule and stop them from being translated into proteins by molecular machines called ribosomes (green), or induce their degradation. Weaver, Zabinsky et al. propose a model whereby these regulatory activities of the microRNAs in a miRISC complex are enhanced by the CED-3 caspase (blue) breaking down proteins (yellow) after they have been translated. This acts as a further level of regulation, and so makes it more likely that developmental gene expression is robustly controlled and the organism will develop correctly.