Here, we investigated whether or not IgG against PTHrP peptides would be detectable in plasma from HLA-A24+ healthy donors and prostate cancer patients, because the antibodies against CTL epitope peptides had already been observed in certain cancer patients and healthy donors (Nakatsura et al, 2002; Ohkouchi et al, 2002). The gene discussed is PTHLH; the disease is prostate cancer.