Early experiments demonstrated that viral vector-associated gene transfer can up-regulate LDLR expression and control hypercholesterolemia in animal models (Andreoletti et al., 2001), and Grossman et al. first conducted a clinical trial in five HoFH patients using retrovirus-mediated gene therapy (NCT00004809) (Table 1). This evidence concerns the gene LDLR and familial hypercholesterolemia.