CASP9 and acute respiratory distress syndrome: In this study, we found that LPS induced the downregulation of Bcl2 and increase of cleaved-caspase 3 and cleaved-caspase 9 in vitro and in vivo, and the induction of apoptosis signaling was alleviated by ERRα overexpression, indicating that inhibition of apoptosis plays a pivotal role in the protect role of ERRα overexpression in ALI.