A gene that, in different variants, increases or decreases the level of atherosclerosis has been identified in mice. The corresponding human gene has been shown to play a role in the development of myocardial infarction. The results of the study is published this week on Nature Genetics Online. Researchers at Karolinska Institutet, in collaboration with the Jackson Laboratory in the USA, AstraZeneca and a Japanese research group, have scrutinised an area on chromosome 1 that is of demonstrable importance to the development of arteriosclerosis. The TNFSF4 gene was identified as the one responsible, as mice with mutations in this gene displayed a lower degree of atherosclerosis, while mice with more active variants of the gene displayed the opposite.Studies of two patient groups revealed that a certain variant of the human homologue of the gene was more common in people who had a history of cardiac infarction than those without.