To generate tumor target cells, DM6, an HLA‐A*02:01+ melanoma cell line, was transfected with tandem minigene constructs (TMCs) encoding the mutated neoantigen peptides from patient MEL21 (DM6‐Mut) or the corresponding wild‐type peptides (DM6‐WT). The gene discussed is HLA-A; the disease is neoplasm.