HHIP and pulmonary emphysema: Cell type-specific pathway analysis on upregulated genes in Hhip+/– lungs indicates significant enrichment of inflammatory and immune pathways in fibroblasts and immune cells at as early as 4 months of age, which may drive subsequently increased lymphocytic inflammation with age-associated emphysema in Hhip+/– mice at 10 months of age (13) (Supplemental Figure 6 and Supplemental Data File 2).