LDLR and serum lipopolysaccharide activity: Contrary to LDL-rich lipoprotein profiles in humans, HDL is the prevalent lipoprotein found in mouse serum representing ≥70% of total lipoproteins by mass41,42, therefore one would expect a minor contribution of the LDL-dependent, LDLR-mediated bacterial lipid uptake pathway in mice, and thus a more modest effect from PCSK9 inhibition in a high-dose endotoxemia model.