Thirty-six patients with clinically diagnosed severe sepsis and low PCT concentrations ('sepsis unlikely') had median PCT concentrations of 0.17 ng/mL (IQR 0.93 and 0.27 ng/mL) on day 0 and 0.13 ng/mL (IQR 0.08 and 0.22 ng/mL). Here, CALCA is linked to Sepsis.