To examine whether RUNX2 mediated VSMC osteoblastic differentiation and diabetic atherosclerotic calcification modulated by the BCAT2–BCKA axis, primary VSMCs were isolated from ApoE−/−/BCAT2fl/fl and ApoE−/−/BCAT2ΔSMC mice and then transfected with negative control small interfering RNA (siRNA) (siNC) or RUNX2 siRNA (siRUNX2) for 48 h followed by supplementation with or without BCKA for 72 h under OM treatment for 14 d. Here, APOE is linked to ocular melanoma.