AUTHOR=Kloetzel Peter M. TITLE=Neo-Splicetopes in Tumor Therapy: A Lost Case? JOURNAL=Frontiers in Immunology VOLUME=Volume 13 - 2022 YEAR=2022 URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2022.849863 DOI=10.3389/fimmu.2022.849863 ISSN=1664-3224 ABSTRACT=The observation that tumor patient derived T cells effective in adoptive T cell therapy are directed against spliced epitopes generated by ligating two distant cleavage products in a reverse proteasomal proteolysis reaction raised some hopes with regard to a general therapeutic and immune relevance of spliced epitopes. Concomitantly, the identification of spliced peptides was also the start of a controversy with respect to their frequency, abundancy and their therapeutic applicability. Here I review some of the recent evidence and discussions raising severe doubts on the immune relevance of spliced peptides. In light of published data, it therefore seems mandatory that before discussing a possible application of tumor neoantigen derived spliced epitopes as targets for adoptive T cell tumor therapy their cell surface expression in the context of HLA-1 proteins has to be unequivocally verified.