Western blot analyses of lysates of myotubes derived from patients with no PAD showed that TLR4 (median, 44; range, 26-53) and cleaved caspase-3 (median, 27; range, 18-33) were upregulated after exposure to simulated ischemia (P < .05; Mann-Whitney U test) compared with nonischemic myotubes from the same patient group (TLR4, median, 14; range, 6-18; cleaved caspase-3, median, 6; range, 4-8). This evidence concerns the gene TLR4 and peripheral arterial disease.