TP53 and chronic obstructive pulmonary disease: On a network basis, TP53 and CEBP transcription factor pathway gene pair network connections were different between COPD and control cohorts as measured by Wilcoxon rank sum test for in- and out-degree (p-value = 7.0E-05), betweenness (p-value = 0.00437), and closeness (p-value = 5.0E-11) (Fig. 2).