RNF121 and cancer: We identified known cargo proteins [various integrins (ITGA5, ITGAV or ITGA1) for AP-2 or ATG9A for AP-4] and also novel potential cargo proteins, such as the ring finger protein 121 (RNF121), a Golgi-localized protein with anti-apoptotic effects in cancer cells (Zhao et al., 2014), the plasma-membrane-localized cation channel TRPM7, the TGN-localized Ca2+ transporter ATP2C2 for AP-1 and the lysosomal Cl−/H+ Antiporter ClC-7 (CLCN7) for AP-3 (Fig. 3C,D).