Associations between SP-D and adverse events in PAD have been previously demonstrated and might also be expected due to observations of SP-D synthesis in vascular smooth muscle cells and endothelial cells (8, 9, 29), reduced atherosclerosis formation with SP-D ablation in mice (9, 23, 30), and the association between genetic polymorphisms affecting SP-D levels and atherosclerotic intima–media thickness (22). This evidence concerns the gene SFTPD and peripheral arterial disease.