Figure 1From: Association of mast cells with lung function in chronic obstructive pulmonary disease 1a. (left) Double immunostaining: tryptase positive mast cells (bright red) in a small airway in a tissue sample from a patient with moderate COPD (GOLD stage 2); bronchial and alveolar type 2 epithelial cells and smooth muscle stain golden brown, magnification × 100; 1b. (right) larger magnification (× 200). Back to article page