Recently, other groups and we have elucidated that hypercholesterolemia promotes hematopoietic stem/progenitor cell (HSPC) proliferation and differentiation, resulting in leukocytosis and plaque progression in hypercholesterolemic apoE−/− [47,48], LDLr−/− [48,49], and SR-BI−/− [50] mice. The gene discussed is SCARB1; the disease is familial hypercholesterolemia.