After serine phosphorylation in the p53 protein, p53 binds to PAI-1 to promote PAI-1 expression, leading to the increase of CXCL1, CXCL2 and CXCR2 in COPD patients (Tiwari et al., 2016), which could induce the influx of neutrophils to infection site. The gene discussed is SERPINE1; the disease is infection.