Notably, CCR4 expression was expressed on approximately 15–25% of CD4+Foxp3+ Tregs from wild-type or Apoe-/- mice (Appendix 1—figure 1A–C), while CD4+Foxp3- non-Tregs from these mice expressed CCR4 at markedly lower levels, suggesting that CCR4 is predominantly expressed on CD4+Foxp3+ Tregs and that hypercholesterolemia does not affect CCR4 expression. Here, APOE is linked to familial hypercholesterolemia.