miR-193a-5p can induce bladder cancer resistance to cisplatin by targeting AP-2α [43]; targeting of MiR-487a via BCRP/ABCG2 enhances the sensitivity of breast cancer cells (MCF7/MX) to mitoxantrone [44]; Studies have shown that MTDH can target and bind miR-26a-5p to play an important role in breast cancer and esophageal squamous cell carcinoma [45, 46]. The gene discussed is ABCG2; the disease is breast cancer.