CYP1B1 and chronic obstructive pulmonary disease: There was substantial overlap in DEGs detected across all three species, with involvement seen in genes with widely studied roles in COPD such as CYP1B1 [31], matrix metalloproteinase 12 (MMP12) [45], and aryl hydrocarbon receptor repressor (AHRR) [46], underscoring the validity of the smoke exposure model in ferrets for evaluation of the lung transcriptome.