TCR-like antibodies, or TCRm antibodies, are antibodies with T cell receptor-like specificities. Since they allow, for the first time, visualization of MHC/peptide complexes on various cells in health and disease, they belong to a new class of antibodies which can be utilized as important tools in molecular immunology. Meanwhile, these antibodies allow the determination of the expressed tumor or viral-related MHC/peptide complexes on the surface of primary tumor cells and metastases or viral infected cells, antigen-presenting cells, etc.