Abstract: The present invention relates to the use of defined polynucleotides to form at least one multi-gene biomarker for producing a multiplex assay as a tool for in vitro detection and/or early detection and/or differentiation and/or progress monitoring and/or evaluation of pathophysiological conditions of a patient, the pathophysiological condition selected from the group consisting of: SIRS, sepsis and its degrees of severity; sepsis-like conditions, septic shock, bacteremia, infective/non-infectious multiorgan failure, early detection of these conditions; focus control, control of surgical rehabilitation of the infection focus; responders/non-responders for a specific therapy, treatment monitoring; distinction between infectious and non-infectious etiology of systemic reactions of the organism, such as SIRS, sepsis, postoperative complications, chronic and/or acute organ dysfunction, shock response, inflammatory response and/or trauma.