miR-21 delivery resulted in downregulation of PTEN and activation of PI3K/AKT pathway, contributing to chemotherapy resistance [17] Wang et al. have reported that hiTDExs led to cisplatin resistance in lung cancer cells via directly increasing glycolysis or transferring Pyruvate Kinase (PKM2) to tumor cell mitochondria and also indirectly re-orchestrated CAFs to change the pH value of the micro-milieu. The gene discussed is PTEN; the disease is neoplasm.