Figure 2.

The importance of being presented. In typical neoantigen identification workflows, candidate tumor antigens are defined from next generation sequencing data (left side). Subsequent in silico binding predictions and in vitro immunogenicity tests identify potential tumor neoepitopes, which, however, are not necessarily presented on the tumor cells themselves. If the target epitope is not present, CD8⁺ T cells cannot identify the transformed cells and the tumor proliferates (middle). In contrast, mass spectrometry-based immunopeptidomics identifies truly presented and actionable epitopes. Immunotherapies targeting these epitopes lead to an immune attack by CD8⁺ T cells and tumor destruction (right side). Created with BioRender.com.