A missing piece of the WFC trafficking complex revealed by cryo-EM.

In this issue of Structure, Zhang et al.1 report high-resolution cryo-electron microscopy (cryo-EM) structures of the human WDR11-FAM91A1-C17orf75 complex, establishing C17orf75 as an integral core subunit and revealing the molecular basis by which this ternary machinery coordinates retrograde vesicle tethering and selective sorting of super-acidic-cluster-containing cargoes.