Interleukin-6 (IL-6), for example, is a physiological marker of pro-inflammatory activity, which can be readily measured in blood, and is involved in the etiology of numerous diseases (e.g., cardiovascular, Type 2 diabetes, certain cancers, autoimmune conditions such as rheumatoid arthritis, and within the brain, the pathobiology of Alzheimer’s). This evidence concerns the gene IL6 and rheumatoid arthritis.