The predisposition of female patients, the duration in hospital, the number of organs affected and DMARDs, the dosage of corticosteroids, the frequency of cases with pulse cyclophosphamide, the blood WBC and eosinophil counts, the concentrations of HB, ALB, CRP, and ESR in the patients with nosocomial infection were significantly greater than that in noninfection patients, determined by univariate analysis (Table 1). The gene discussed is ESR1; the disease is nosocomial infection.