Transport between the trans-Golgi network (TGN) and endosomes takes place in clathrin-coated vesicles (CCVs). The clathrin-adaptor protein AP-1 and members of the GGA protein family are essential adaptors in this process, but do they act in concert, in parallel or in opposite directions? In a Commentary on p. 763, Ina Hinners and Sharon Tooze discuss the structure and function of these adaptors and try to answer this question. Early work suggested that AP-1 complexes form at the TGN and function in TGN-to-endosome (anterograde) transport. The observation that cargo molecules do not get stuck at the TGN in mice lacking an AP-1 subunit cast doubt on this idea; GGA proteins instead were proposed to regulate anterograde transport, since they interact with clathrin and compromise anterograde transport when mutated. GGA proteins interact with AP-1, however,and are not stable components of CCVs. Hinners and Tooze therefore argue that both adaptors function in anterograde transport. They propose that transient association of GGA proteins with CCVs recruits AP-1 during anterograde transport but that AP-1 is also part of a distinct retrograde transport mechanism.