IL6ST and chronic obstructive pulmonary disease: Inflammation is important in the pathogenesis of stable COPD.1 Environmental stress such as cigarette smoke activates the innate immune response which may drive COPD inflammation.2 Interleukin 6 (IL-6) is a multifunctional pro-inflammatory cytokine1 that acts via two molecules: the IL-6R (IL-6 receptor) and gp130.3 Soluble gp130 (sgp130) inhibits IL-6 trans-signalling via the soluble IL-6R (sIL-6R) and classic signalling via the membrane bound IL-6R (mIL-6R).4