Omalizumab reduced germline Cϵ and IL-4Rα mRNA levels in ~ 50% of tonsillar samples. B cells were treated with IL-4 + anti-CD40 in the presence or absence of 1 μg/mL omalizumab (Om). After 3 days RNA was isolated and quantified by qRT-PCR for (A) germline Cϵ and IL-4Rα mRNA. (B) CD23a and CD23b mRNA. Data are expressed as the mean ± SEM (n = 5 tonsils for group 1 and n = 5 tonsils for group 2). Statistically significant differences (p values) were determined by t-test.