Correlation analysis showed that plasma IL‐22 levels were negatively correlated with CT scores of IPF (r2 = 0.358, p = 0.005; Figure 1E), and positively correlated with a pulmonary function parameter, FEV1% pred (r2 = 0.380, p = 0.033; Figure 1F), suggesting a negative correlation between blood IL‐22 and the disease severity of IPF. This evidence concerns the gene IL22 and idiopathic pulmonary fibrosis.