IL1B and infection: The transcript levels for Il1a (ANOVA: F: 13.29, P < 0.001), Il1b (ANOVA: F: 11.37, P < 0.001), Il33 (ANOVA: F: 3.452, P = 0.028) and Ccl20 (ANOVA: F: 6.824, P = 0.001) were all elevated within 6 h of infection relative to naïve pinnae (Fig. 4A–D), but Il1a, Il1b and Il33 had declined to baseline levels by 24 h (Fig. 4A–C).