Taken together, further studies with conditional ablation of HHIP in adult tissues and cell type–specific ablation of HHIP in human lung organoid models or species with both epithelial and mesenchymal expression of HHIP, such as rats, would elucidate the developmental, compartment-specific effect of HHIP in COPD pathogenesis. Here, HHIP is linked to chronic obstructive pulmonary disease.