Lung necroptosis status. (a) Representative microscopic images of phosphorylated mixed lineage kinase domain-like pseudokinase (pMLKL, the indicator of necroptosis, marked by the red arrow, 200×) in lung tissues assayed using immunohistochemistry analysis and the sum of the pMLKL signal intensity. (b) Representative gel images of cleaved caspase-8 and actin (the internal standard) in lung tissues assayed using immunoblotting assay and the relative band density of cleaved caspase-8/actin in lung tissues. All assays were measured at 24 h after endotoxin or normal saline administration. Sham: the normal saline group. KCF: the normal saline plus the KCF18 peptide group. SEM: the normal saline plus the SEM18 peptide group. Endo: the endotoxin group. EKCF: the endotoxin plus the KCF18 peptide group. ESEM: the endotoxin plus the SEM18 peptide group. Data were obtained from five mice in each group and presented as the mean ± standard deviation. * p < 0.05, versus the Sham group. # p < 0.05, versus the Endo group. † p < 0.05, the ESEM group versus the EKCF group.