The PTEN/mTOR pathway is a target of miR-21-5p; knockdown of miR-21-5p decreased the number of neuronal deletions and improved the cognitive impairment caused by epilepsy, which suggested that the miR-21-5p/PTEN/mTOR axis might be a potential target for preventing and treating epileptic damage (Tang et al., 2018). The gene discussed is MTOR; the disease is epilepsy.