ALDH2 and chronic obstructive pulmonary disease: There is a paucity of experimental validation and biological functional verification that directly link these biomarkers (ALDH2, ASGR2, and CYP1B1) to lactylation, coupled with potential batch effects in public databases (e.g., data from acute exacerbation phases, which fail to fully capture the heterogeneous features of chronic obstructive pulmonary disease).