We have tested HLA-B expression at the serological level from 80 epithelial cancer patients, including 10 colon cancer patients, but because of its lower frequency in Japanese, PBMCs from only 10 HLA-B46+ cancer patients (five lung cancer and five prostate cancer patients) and four HLA-B46+ HD served as subjects for the CTL induction assay. The gene discussed is HLA-B; the disease is malignant colon neoplasm.