Pharmacological inhibition of PCSK9 also protected against the effects of sepsis in mice; an antibody that blocked PCSK9 blunted inflammatory cytokines and improved survival in a polymicrobial peritonitis model.4 These beneficial effects were absent when the gene for the LDLR was deleted, indicating that PCSK9 inhibition altered responses to LPS through the LDLR.4 However, in a second study, neither Pcsk9 deletion nor PCSK9 antibodies protected mice against LPS-induced mortality.41 This evidence concerns the gene PCSK9 and peritonitis.