“…Systemic inflammation, to varying degrees, affects between 50% and 70% of those with COPD and lung cancer [20,22,26]. There are then bidirectional effects between smoking-induced airway inflammation and "inherent" systemic inflammation, where the latter may be responsible for persisting neutrophilic inflammation in the lungs [16]. This, in turn, contributes to the aberrant repair-remodelling processes underlying COPD that result from a protease-antiprotease imbalance, excessive oxidative stress and progressive DNA damage [16].…”