Pepsin detected in the tonsillar hypertrophy tissues.

<p><b>A)</b> Pepsin was expressed in the tonsil tissue. Stomach tissues were used as positive control for pepsin detection. Other tissues were used as negative control. <b>B)</b> Pepsin staining levels were different from each patient. β-actin was used for housekeeping control. LN, lymph node. Thy, thyroid. Parotid g, parotid gland. SG, salivary gland. <b>C)</b> Pepsin-positive cells localized below the surface epithelium, mainly in the crypt regions (a and b), also surrounding the more negative germinal centers (c and d), and surrounding the lymphoid follicle with excessive developing fibrosis (e and f). <b>D)</b> Stomach sections showed a typical pattern of pepsin staining (a), but not in the lymph node (b) and thyroid (c).