Although HDAC3 can act as a transcriptional repressor to influence IL-33 expression in many diseases, including multiple sclerosis and allergic asthma (29), it is still unclear whether the inhibitory effect of butyrate is due to the direct acetylation of the Il33 gene or indirectly through the transcriptional activation/suppression of other targets that can alter the IL-33 expression. This evidence concerns the gene HDAC3 and allergic asthma.