TGFB1 and bronchiolitis obliterans syndrome: We found that the levels of IL‐8 (Figure 4a), IL‐17 (Figure 4b), TNF‐α (Figure 4c), and TGF‐β (Figure 4d) were significantly increased in the supernatant of co‐cultured cells treated with IgG obtained from BO patients with high ANCA expression.