Turner JH, et al. - Authors evaluated the ability of mucus T helper 2 (Th2) biomarkers to predict chronic rhinosinusitis (CRS) disease severity and clinical characteristics. They noted that in sinonasal mucus the Th2-associated cytokines, IL-5 and IL-13, were detectable and Th2-high and Th2-low CRS could be defined by using their levels. Stratification of CRS subgroups could be facilitated with the identification of Th2-high and Th2-low endotypes using mucus-based biomarkers. This identification could also help to guide personalized therapies.