Plasma cAT levels were significantly elevated in most patients with malignant tumors, including those with breast carcinomas, hepatocellular carcinomas, lung carcinomas, esophageal carcinomas, gastric cancer, colon cancer, rectal cancer, pancreatic cancer, ovarian carcinomas, bladder carcinomas, uterine myomas, thyroid carcinomas and prostate carcinomas (p < 0.01), but not in those with cervical cancer or endometrial carcinomas. The gene discussed is CAT; the disease is colonic neoplasm.