IL15 and infection: When comparing the levels of these 11 biomarkers longitudinally in the subset of patients with critical disease during ICU admission and later on in the same patients when they recovered from infection and exited from the ICU to the regular hospital ward, the T cell–associated biomarkers IL-2 and IL-10, the sepsis biomarker sST2, and the monocyte/macrophage activation–associated biomarker IL-15 declined upon patient recovery (Supplemental Figure 15).