The grayscale value of positive cells of β-catenin (mTOR signaling pathway) in Birt–Hogg–Dubé patients was lower than in patients with simple pulmonary bulla (66.467 ± 1.142 vs. 114.933 ± 1.307, Figures 8(e) and 8(f)). The gene discussed is MTOR; the disease is Pulmonary bulla.