Perturbagen signature analyses likewise highlighted small-molecule regulators of TGF-β1-associated pathways.<h4>Interpretation</h4>These integrative genomic and transcriptomic analyses nominate TGF-β1-SMAD/MAPK signaling as a biologically plausible axis of genetic susceptibility to PM<sub>2.5</sub> in pediatric asthma. This evidence concerns the gene TGFB1 and asthma.