TNNI3 and susceptibility to pneumonia measurement: As shown in Table 4, the level of serum cTnI was positively correlated with age (R = 0.208, P = 0.027), CRP (R = 0.273, P = 0.008), CREA (R = 0.258, P = 0.009), serum IL6 level (R = 0.302, P = 0.037), pneumonia severity index (PSI) score (R = 0.210, P = 0.025), APACHE II score (R = 0.296, P = 0.001) and SOFA score (R = 0.323, P < 0.001) and negatively correlated with lymphocyte counts (R = -0.245, P = 0.012) in all patients.