Then, the tumor tissues taken out from mice were used to detect the expression of circNFIX, miR-34a-5p and NOTCH1. The qRT-PCR results showed that the expression of circNFIX and NOTCH1 was significantly reduced in the si-circNFIX group compared with NC group, while miR-34a-5p was remarkably upregulated after treatment with si-circNFIX. The gene discussed is NOTCH1; the disease is neoplasm.