IL6 and rheumatoid arthritis: T cells with the minor CC genotype show impaired classic IL-6 signaling due to enhanced a disintegrin and metalloproteinase (ADAM)-mediated shedding of the membrane-bound IL-6 receptor (mbIL-6R) compared to the AA genotype and are associated with protection from development of rheumatoid arthritis and type 1 diabetes (T1D) (12).