More recently, periostin levels were associated with the severity of viral bronchiolitis, as children with severe pulmonary hypertension had high levels of this protein as compared to children with mild pulmonary hypertension (8,887 ± 1,582 pg/ml vs. 5,016 ± 1,017 pg/ml) (99). This evidence concerns the gene POSTN and pulmonary arterial hypertension.