APOA1 and endothelial dysfunction: Using unsupervised clustering, we were then able to phenotype sepsis patients into Hypolipoprotein and Normolipoprotein phenotypes, with the Hypolipoprotein phenotype being characterized by lower lipoprotein levels (lower HDL-C and ApoA-I), and increased endothelial dysfunction (ICAM-1) as well as higher SOFA scores.