We leveraged this property in ARTEMIS by co-transducing HLA-A*02:01, A*11:01, or A*24:02 SCDs with a lentivirus encoding a target protein, yielding a thousands-deep, allele-specific ligandome from HEK293 cells plus peptides from the targeted proteins: E6 and E7 from HPV16, an HIV Env gp140, the truncated, tumor-associated form of MCV LT, or the tumor-associated antigen MSLN in its native, proprotein form (Table 2, Figures 10, 11). Here, ERVW-1 is linked to neoplasm.