The natural frequency and functional phenotype of circulating anti-ALK CD8 T cell precursors in the peripheral blood of healthy donors and ALK-positive ALCL patients was assessed by tetrameric MHC/peptide analysis, IFN-γ ELISPOT assay, and in vitro lysis of ALK-positive target cells [55]. The gene discussed is CD8A; the disease is anaplastic large cell lymphoma.