Fig. 4

Pre- and postnatal exposure to epigenetic-mediated asthma stimulators and their outcomes. a Asthma triggers comprising tobacco smoking, house dust mite, air pollution, and lifestyle can negatively regulate the fetus epigenome. b Monozygotic twins that were exposed to these triggers in utero may or may not develop childhood asthma. c The microbiome may develop a protective epigenome in the offspring against asthma. d External factors can affect the person after birth. e The epigenetic changes seen in early life may affect the phenotype in childhood or adulthood, and those who showed the symptoms in childhood may recover in adulthood while those who were healthy children may become adults with asthmatic symptoms