LDLR and familial hypercholesterolemia: As most hypercholesterolemia patients do not carry LDLR mutations, we also investigated cellular LDL uptake in PBMCs from 20 biobank donors with elevated LDL-c levels (LDL-c > 5 mM) (hLDL-c) and from 19 donors with normal LDL levels (LDL-c 2–2.5 mM) (nLDL-c) from the FINRISK population cohort (Borodulin et al., 2018; Table S2).