IL13 and chronic rhinosinusitis without nasal polyps: As shown in Fig. 1, CRSsNP (median 15 pg/ml, range 2–92 pg/ml; p < 0.01 vs. controls and vs. NP) as well as NP (median 10 pg/ml, range 4–62 pg/ml; p < 0.001 vs. controls) presented reduced amounts of IL-13 (controls: median 19 pg/ml, range 10–32 pg/ml).