VEGFD and pneumothorax: Among patients with S-LAM, significant differences were observed in age (P = 0.0204), BMI (P = 0.0276), menopause (P = 0.0068), smoking status (P = 0.0049), pneumothorax (P = 0.0213), AMLs (P < 0.0001), retroperitoneal LAMs (P < 0.0001), chylous effusion (P < 0.0001), HRCT grading (P < 0.0001), FEV1%pred (P < 0.0001), FEV1/FVC (P < 0.0001), DLco%pred (P < 0.0001), PaO2 (P < 0.0001) and P(A-a)O2 gradient (P < 0.0001) and 6MWD (P = 0.0369) across different VEGF-D groups.