Immunopeptidomics is an approach for directly profiling the repertoire of major histocompatibility complex (MHC)-presented peptide antigens using MS, which has been proven to benefit vaccine development for both cancer and infections.148,149 Briefly, MHC-bound peptides are purified from patient samples or cultured cells that were infected with pathogens; the eluted peptides are then subjected to MS for peptide identification. Here, HLA-C is linked to cancer.