Sepsis is a complex syndrome that causes lethal organ dysfunction due to an abnormal host response to infection. No drug specifically targeting sepsis has been approved. The heterogeneity in sepsis pathophysiology hinders the identification of patients who would benefit, or be harmed, from specific therapeutic interventions. Recent clinical genomics studies have shown that sepsis patients can be stratified as molecular subtypes, or subclasses, with clinical implications. Classifying sepsis patients as molecular subtypes revealed that a poor prognosis subtype was characterized by immunosuppression and septic shock. Therefore, it has become essential to identify patients who may benefit from or be adversely affected by specific treatments, thereby identifying bona fide treatable traits or endotypes. The goal of this study is to assist the physician at the bedside in tailoring the treatment of an individual patient suffering from sepsis by generating rapid molecular information about immune status.