MB and Sepsis: Slow‐twitch specific mRNAs, including myoglobin (Mb), troponin I type 1 (Tnni1), and myosin heavy chain 7 (Myh7) were decreased in WT skeletal muscle (Mb, P < 0.0001; Tnni1, P < 0.05; and Myh7, P < 0.05) after sepsis induction, but mRNA expressions of Tnni1 and Myh7 were increased in PD‐1 KO septic mice (Mb, not significant; Tnni1, P < 0.0001; and Myh7, P < 0.05).