HNF4A and asthma: Taken together, our findings demonstrate that following OVA challenge, interaction of HNF4α and PGC1α increased methylation frequency of Vnn1 at promoter regions and thus upregulated its expression, resulting in activation of the PI3K/Akt/NFκB signaling being responsible for ROS production and inflammatory mediators release, and finally resulting in asthma occurrence in the IUGR mice.