ATP6V1E1 and chronic obstructive pulmonary disease: We found that the expression of ATP6V1E1 in the lung tissue was increased in the COPD group compared with normal controls by Western blot (p<0.05, Supplementary file Figure 7); no significant difference was seen between the control group and ATG5myeΔ group; compared with the wild-type COPD group, ATP6V1E1 expression was decreased in the lung tissues of ATG5myeΔ COPD mice (p<0.05, Supplementary file Figure 7), suggesting that ATP6V1E1 may be an important factor in the development of COPD due to macrophage autophagy.