Neoantigens form as a direct result of genetic alterations in cancer cells. These alterations can include point mutations, insertions, deletions, and gene fusions. When these genetic changes occur, they can lead to the production of abnormal proteins. During the process of protein degradation, these abnormal proteins are broken down into peptide fragments, some of which are presented on the cell surface by major histocompatibility complex (MHC) molecules, becoming neoantigens.
