After excluding the 36 patients with PAD, HO-1 levels were found to be significantly higher in 192 patients with CAD than in 182 without CAD (median 0.45 versus 0.35 ng/mL, P < 0.05) (Figure 2) and were less frequently <0.35 ng/mL in patients with CAD than in those without CAD (36% versus 49%, P < 0.025). The gene discussed is HMOX1; the disease is peripheral arterial disease.