The role in the susceptibility for abdominal aortic aneurysms of the MTHFR c.665C>T (p.Ala222Val) variant, previously reported as C677T, was investigated by a number of case–control studies showing more robust associations in some than in others (Narayanan et al. 2013). This evidence concerns the gene MTHFR and abdominal aortic aneurysm.