Neoantigen peptide mimics

A polynucleotide encoding at least one or more polypeptide fragments selected from:

• a) a capicua transcriptional repressor (CIC) polypeptide fragment of nine amino acids in length comprising:
• an amino acid substitution at amino acid position 2 of the fragment, amino acid position 9 of the fragment, or both, and
• an arginine to tryptophan amino acid substitution at a position corresponding to position 215 (R215W) of SEQ ID NO:
• 102, wherein the R215W substitution is at amino acid position 8 of the fragment;
• b) a catenin beta 1 (CTNNB1) polypeptide fragment of nine amino acids in length comprising:
• an amino acid substitution at amino acid position 2 of the fragment, amino acid position 9 of the fragment, or both, and
• i. a serine to cysteine amino acid substitution at a position corresponding to position 33 (S33C) of SEQ ID NO:
• 103, wherein the S33C substitution is at amino acid position 4 of the fragment, or
• ii. a serine to phenylalanine amino acid substitution at a position corresponding to position 37 (S37F) of SEQ ID NO:
• 103, wherein the S37F substitution is at amino acid position 8 of the fragment;
• c) a v-erb-b2 erythroblastic leukemia viral oncogene homolog B (ERBB2) polypeptide fragment of nine amino acids in length comprising:
• an amino acid substitution at amino acid position 2 of the fragment, amino acid position 9 of the fragment, or both, and
• a valine to isoleucine amino acid substitution at a position corresponding to position 842 (V842I) of SEQ ID NO:
• 104, wherein the V842I substitution is at amino acid position 3 of the fragment;
• d) a kirsten rat sarcoma (KRAS) polypeptide fragment of nine amino acids in length comprising:
• an amino acid substitution at amino acid position 2 of the fragment, amino acid position 9 of the fragment, or both, and
• a glycine to alanine amino acid substitution at a position corresponding to position 12 (G12A) of SEQ ID NO:
• 105, wherein the G12A substitution is at amino acid position 7 of the fragment;
• or
• e) a phosphatase and tensin homolog (PTEN) polypeptide fragment of ten amino acids in length comprising:
• an amino acid substitution at amino acid position 3 of the fragment, amino acid position 10 of the fragment, or both, and
• an arginine to cysteine amino acid substitution at a position corresponding to position 173 (R173C) of SEQ ID NO:
• 107, wherein the R173C substitution is at amino acid position 1 of the fragment,
• wherein the one or more polypeptide fragment binds to HLA-A*02:01.