GSTM1 and susceptibility to pneumonia measurement: Several clinical characteristics, including age, gender, duration of fever, length of hospitalization, hemoglobin (Hb), albumin (ALB), lactate dehydrogenase (LDH), the number of pneumonia lobes, pulmonary consolidation lobes, the proportion of invasive mechanical ventilation (IMV), oxygen therapy, bronchoalveolar lavage, use of intravenous immunoglobulin (IVIG), and use of glucocorticoids were found to have statistically significant (p < 0.05) in the univariate analysis.