The gene most strongly regulated by miR-29 is IL12B (encoding IL-12/23 p40) while IL23A (encoding IL-23 p19) is indirectly targeted through suppression of its transcription factor ATF2 and mice deficient of this miRNA develop a more severe Th17 driven colitis on DSS exposure.9 Microbiota can also impact on DC miRNA expression. This evidence concerns the gene IL23A and colitis.