Plays a critical role in the regulation of cDC1-mediated cross-presentation of viral and tumor antigens in dendritic cells (PubMed:30409884). Mechanistically, acts near the plasma membrane and interacts with endosomal membranes to promote endosomal-to-cytosol antigen trafficking (PubMed:30409884). Also plays a role in B-cell survival through regulation of autophagy (PubMed:30257884). Interacts with HSP90AB1. Highly expressed in immune tissues, especially B lymphocytes. Mice are unable to cross-present in vivo (PubMed:30409884). In addition, affects the development of B-cells with a block in the transition between the pro- and pre-B cell stages in bone marrow (PubMed:30257884).