In addition, a survey of HLA in patients with abdominal aortic aneurysms in Japan pointed out an association with MHC class I and reported that HLA-B52 was more common in patients with abdominal aortic aneurysms who had aorto-iliac occlusive disease than those who did not [28]. This evidence concerns the gene HLA-C and abdominal aortic aneurysm.