TAPBP and cancer: Therapeutically, several of the components of the APP machinery could be targeted in order to enhance the immunogenicity of cancer: the ubiquitin-proteasome degradation pathway, cytosolic peptidases, the TAP transporter, the peptide loading complex, peptide editing chaperones such as Tapasin or TAPBPR, ER aminopeptidases, and the MHCI themselves.