CHI3L1 and asthma: Comparison between tryptase stimulated cells and non-stimulated cells using RT2 PCR profiler array for asthma and allergy and wound healing pathways showed that tryptase alone upregulated AREG (fold difference 6.35, p = 0.004), IL12B (fold difference 4.00, p = 0.02), CCL2 (fold difference 4.00, p = 0.03), CHI3L1 (fold difference 3.17, p = 0.03) and CCR4 (fold difference 2.52, p = 0.02) on gene level.