This work may contribute to the field of cell-based immunotherapy in the following four aspects: (1) providing the feasibility to use a camel VHH nanobody as a therapeutic scaffold targeting MHC-associated peptides in cancer, (2) constructing large dromedary camel VHH phage libraries for the discovery of TCRm nanobodies, (3) targeting an MHC-associated peptide in governing optimal CAR-T activity without prior knowledge of the complex structure, and (4) inhibiting solid tumor growth in mice with TCRm nanobody-based CAR-T cells while the MHC-associated peptide density on tumor cells is low. Here, HLA-C is linked to cancer.