Rag1−/− mice with Dpp4+/+ (Dpp4T‐WT) or Dpp4−/− T cells (Dpp4T‐∆) were then infected with adenoassociated viruses overexpressing proprotein convertase subtilisin/kexin type 9 (PCSK9) and fed a HFD to induce atherosclerosis.[14] Flow cytometric detection of splenic cells confirmed that DPP4 was specifically deleted in CD4+ and CD8+ T cells, but not in CD3 cells (Figure S8a–e, Supporting Information). Here, PCSK9 is linked to atherosclerosis.