Clinicopathological variables, including sex (male vs. female), smoking (yes vs. no), length of operation, field of lymph node dissection (three vs. two), and IL-10 -819 polymorphism (T/T vs. C/T + C/C) were entered into a multivariate logistic regression model to identify factors influencing pneumonia (Table 4). This evidence concerns the gene IL10 and pneumonia.