Antigen cross-presentation is a critical step in the elicitation of cell-mediated immune responses. Much research has been aimed at manipulating antigen cross-presentation to improve tumor immunotherapy and vaccination. In this issue of Science Translational Medicine, Saccheri et al. describe a mechanism for spurring successful antitumor responses by enhancing the transfer, to antigen-presenting cells, of tumor-specific antigens that leave the cancer cells via gap junctions induced by Salmonella infection of the melanoma tumor. Salmonella turns from foe to friend by promoting cross-presentation for strong antitumor immunity and tumor eradication.