The stepwise analysis is shown in Table 4, suggesting that a high level of IL-6 mRNA at POD 0 is an independent indicator of poor prognosis (as are days of ventilator dependence, days of ICU stay, and days of SIRS (p < 0.0001); a high level at POD3 predicted the onset of pneumonia (p = 0.021). The gene discussed is IL6; the disease is susceptibility to pneumonia measurement.