The intracellular accumulation of various chemotherapy drugs is reduced (87, 91) and circ_MTO1 (hsa_circ_0007874) is downregulated in monastrol drug-resistant cell lines (MDA-MB-231R and MCF-7R), which regulates the TRAF4/Eg5 axis by targeting the Eg5 protein, binding TRAF4 to the Eg5 gene and thereby inhibiting BC cell activity and promoting monastrol-induced cytotoxicity (92). The gene discussed is TRAF4; the disease is breast cancer.