Though many investigators have studied the utility of PCT in predicting mortality in various types of pneumonia including CAP [5–7, 17–26], HCAP [37, 38], VAP [39–43] and HAP [44], their results were not consistent While some reported PCT to be a reliable predictor for mortality [17–26], others showed that PCT was inferior to other markers such as PSI, CURB-65 [52], CRP, IL-6 [53], or BUN/albumin ratio [54] for predicting mortality. Here, IL6 is linked to susceptibility to pneumonia measurement.