Cellular response pathways to IFN-γ and TNF, and chemokine response were upregulated in IPF compared to SSc-ILD natural killer cells (Figures 3F, H); whereas regulation of metalloendopeptidase activity, and positive regulation of type I interferon production were upregulated in SSc-ILD compared to IPF natural killer cells (Figures 3G, H, Supplemental File 3). This evidence concerns the gene IFNG and interstitial lung disease.