TLR4 and pulmonary emphysema: TLR are linked to emphysema, and TLR also play a role in autophagy regulation.[60,61] An experimental study by CH concluded that there is a link between TLR4 and autophagy, and in vitro and in vivo experiments using lung tissues from patients with COPD and Tlr4 mutant and Tler4-deficient mice demonstrated that TLR4 inhibits the development of CS-induced emphysema by suppressing autophagy.[62]