In a pooled analysis of the measurements from all 40 study participants, PBR and microcirculation parameters (MFI and PPV) were correlated with several markers of critical/acute illness (Table 2), including mean arterial pressure (MAP), C-reactive protein (CRP), interleukin-6 (IL-6), and procalcitonin (PCT) levels, as well as SIRS and SOFA scores. The gene discussed is IL6; the disease is systemic inflammatory response syndrome.