As a reliable carrier, MSC-EVs can encapsulate miR-137, a small molecule that can be introduced into BTBR mice by intranasal administration or co-cultured with microglia in vitro, thereby alleviating autism-like behaviors and inhibiting neuroinflammatory responses in the brain and microglia through the TLR4/NF-κB pathway in mice. The gene discussed is TLR4; the disease is autism.