PCSK9 and Sepsis: Accordingly, given their respective contributions to sepsis pathobiology and the potential for interaction during systemic inflammation among critically ill patients, we sought to test (1) whether PCSK9 LOF genotype was independently associated with markers of endothelial dysfunction after accounting for serum lipoprotein concentrations and (2) whether these effects were causally mediated in a large pediatric cohort of septic shock.