ATP5F1B and metabolic dysfunction-associated steatohepatitis: Zhao et al. demonstrated that mitochondria-localized circRNA SCAR directly binds ATP synthase β subunit (ATP5B) in non-alcoholic steatohepatitis (NASH), disrupting cyclophilin D (CypD)-mPTP interaction to inhibit pathological mPTP opening, thereby reducing mitochondrial ROS (mROS) release and ultimately alleviating fibroblast activation and hepatic fibrosis.