XAF1 and chronic obstructive pulmonary disease: Analysis of the expression of 10 genes—CMPK2, EPSTI1, IFI44, IFI44L, IFIT1, IFIT3, MX1, OAS2, RSAD2 and XAF1—in the COPD samples compared to samples from normal controls showed a statistically significant difference in the expression level distribution between COPD patients and normal controls.