The analysis of the correlations between the serum periostin levels and the rate of FEV1 reduction at the time of BOS diagnosis revealed that the serum periostin levels at the time of BOS diagnosis were positively correlated with the reduction in FEV1 (%) (r = 0.745, p < 0.001) (Figure 5A). This evidence concerns the gene POSTN and Buschke-Ollendorff syndrome.