A method for assessing the usefulness of a disease specific amino acid modification within a peptide or polypeptide expressed in a diseased cell for immunotherapy, wherein the disease specific amino acid modification is identified by identifying disease specific somatic mutations by sequencing genomic DNA and/or RNA of diseased tissue or one or more diseased cells, the method comprising ascertaining one or more of the following: (i) ascertaining whether the same or different fragments of the peptide or polypeptide comprising the disease specific amino acid modification are presented in the context of MHC molecules of different classes and/or when presented in the context of MHC molecules are reactive with T cells restricted to different MHC classes, wherein presentation of the same or different fragments of the peptide or polypeptide comprising the disease specific amino acid modification in the context of MHC molecules of different classes and/or reactivity of the same or different fragments of the peptide or polypeptide comprising the disease specific amino acid modification when presented in the context of MHC molecules with T cells restricted to different MHC classes indicates that the disease specific amino acid modification is useful for immunotherapy, (ii) ascertaining whether a fragment of the peptide or polypeptide comprising the disease specific amino acid modification when presented in the context of the same MHC molecule is reactive with T cells having different T cell receptors, wherein reactivity of a fragment of the peptide or polypeptide comprising the disease specific amino acid modification when presented in the context of the same MHC molecule with T cells having different T cell receptors indicates that the disease specific amino acid modification is useful for immunotherapy, and/or (iii) ascertaining whether the same or different fragments of the peptide or polypeptide comprising the disease specific amino acid modification are presented in the context of different MHC molecules of the same class and/or when presented in the context of different MHC molecules of the same class are reactive with different T cells restricted to the same MHC class, wherein presentation of the same or different fragments of the peptide or polypeptide comprising the disease specific amino acid modification in the context of different MHC molecules of the same class and/or reactivity of the same or different fragments of the peptide or polypeptide comprising the disease specific amino acid modification when presented in the context of different MHC molecules of the same class with different T cells restricted to the same MHC class indicates that the disease specific amino acid modification is useful for immunotherapy; wherein, preferably, (a) the MHC molecules of different classes are MHC class I molecules and MHC class II molecules and/or the T cells restricted to different MHC classes are CD4+ and CD8+ T cells, and/or (b) the different MHC molecules of the same class are different MHC class I molecules and/or the different T cells restricted to the same MHC class are different CD8+ T cells. (i) ascertaining whether the same or different fragments of the peptide or polypeptide comprising the disease specific amino acid modification are presented in the context of MHC molecules of different classes and/or when presented in the context of MHC molecules are reactive with T cells restricted to different MHC classes, wherein presentation of the same or different fragments of the peptide or polypeptide comprising the disease specific amino acid modification in the context of MHC molecules of different classes and/or reactivity of the same or different fragments of the peptide or polypeptide comprising the disease specific amino acid modification when presented in the context of MHC molecules with T cells restricted to different MHC classes indicates that the disease specific amino acid modification is useful for immunotherapy, (ii) ascertaining whether a fragment of the peptide or polypeptide comprising the disease specific amino acid modification when presented in the context of the same MHC molecule is reactive with T cells having different T cell receptors, wherein reactivity of a fragment of the peptide or polypeptide comprising the disease specific amino acid modification when presented in the context of the same MHC molecule with T cells having different T cell receptors indicates that the disease specific amino acid modification is useful for immunotherapy, and/or (iii) ascertaining whether the same or different fragments of the peptide or polypeptide comprising the disease specific amino acid modification are presented in the context of different MHC molecules of the same class and/or when presented in the context of different MHC molecules of the same class are reactive with different T cells restricted to the same MHC class, wherein presentation of the same or different fragments of the peptide or polypeptide comprising the disease specific amino acid modification in the context of different MHC molecules of the same class and/or reactivity of the same or different fragments of the peptide or polypeptide comprising the disease specific amino acid modification when presented in the context of different MHC molecules of the same class with different T cells restricted to the same MHC class indicates that the disease specific amino acid modification is useful for immunotherapy;