Processing bodies (P bodies) are discrete cytoplasmic foci to which mRNA is routed for degradation. In mammalian cells, they are also associated with miRNA-induced translational silencing and siRNA-induced mRNA degradation. In a recent issue of Molecular Cell, Ding and coworkers described an argonaute-interacting protein that appears to promote the assembly of P bodies in C. elegans (Ding et al., 2005).