IL6 and chronic obstructive pulmonary disease: Accelerated lung aging in COPD patients also causes senescent cells in the lung to release inflammatory proteins, including tumor necrosis factor alpha (TNF-α), Interleukin (IL)-1, IL-6, chemokine (C-X-C motif) ligand 8 (CXCL8), chemokine (C-C motif) ligand 2 (CCL2) and matrix metalloproteinases (MMPs).