The results showed that the pretreatment of mice with elemene, DOX, and their combination revealed that the expression level of CDK8 gene in the serum of mice pretreated with DOX was higher than that of the model group, and the expression level of the CDK8 gene in tumor tissues of mice in the combination group was lower than that in the DOX group but higher than in the elemene group. The gene discussed is CDK8; the disease is neoplasm.