The protein concentration was lowest in the mild stenosis group, at 37.68 ng/mL; it was 45.46 ng/mL in the mild-to-moderate stenosis group; it reached 55.22 ng/mL in the moderate stenosis group; and it was highest in the severe stenosis group, at 79.95 ng/mL.<h4>Conclusion</h4>There is a correlation between plasma CACNA2D1 protein concentration and the degree of coronary artery stenosis, demonstrating that it has the potential to serve as a biomarker. Here, CACNA2D1 is linked to coronary stenosis.