Another gene has been identified that appears to increase risk of Alzheimer’s. The gene, MTHFD1L, is located on chromosome six. Comparison of the genomes of 2,269 people with late-onset Alzheimer's disease and 3,107 people without the disease found those with a particular variation in this gene were almost twice as likely to develop Alzheimer's disease as those people without the variation. The gene is involved in influencing the body's levels of homocysteine (high levels are known to be a strong risk factor), and have also been implicated in coronary artery disease.