PBMCs from HTLV-1 infected patients were incubated with and without HTLV-1 Tax peptide in the presence of anti CD48 antibodies and the effect on in-vitro CTL response in terms of perforin production measured in 6 ATLL and 5 AC subjects in 7 independent experiments. Here, CNTN2 is linked to adult T-cell leukemia/lymphoma.