IHC analysis further revealed that overexpressing circSEPT9 could up-regulate the expressions of LIF, P-STAT3, ID1 and MDM2 as well as decrease of the levels of P53 and P21 in tumor tissues of mice, while circSEPT9 silencing caused the opposite effects (Additional file 2: Figure S3). The gene discussed is MDM2; the disease is neoplasm.