To further investigate the role of exosomal Rmrp in the prognosis of SII and secondary pneumonia, we collected exosomes from in vitro‐cultured MLE‐12 cells and administered them intratracheally to sham and CLP mice, which were subsequently infected with P. aeruginosa 2 days after CLP (Figure S21A, Supporting Information). Here, RMRP is linked to susceptibility to pneumonia measurement.