PCSK9 and diabetes mellitus: Upon obtaining the relevant mouse models, one can subject them to relevant models of diabetes(e.g., either STZ-induced T1D or special diet-induced T2D) or atherosclerosis (e.g., through induction of proprotein convertase subtilisin/kexin type 9 (PCSK9) under a high-cholesterol diet), which can be further combined with the femoral artery ligation to induce HLI, the most commonly used model for PAD [68, 250–253].