Tumor markers are defined as the antigens and biotic activators which are the abnormally expressed products, and those substances are produced by the related gene of the tumorous tissue and cell, not by normal tissue.

• 肿瘤标志物是指肿瘤组织和细胞的相关基因及其产物异常表达所产生的抗原和生物活性物质，正常组织不产生或产量甚微，但肿瘤患者组织、体液和排泄物中浓度可能较高，而易被检出。