Figure 3. IAPP-positive PPoma (A–D) and IAPP-negative non-functioning tumor (E–H). This PPoma revealed many strongly PP positive cells (D) and scattered moderately IAPP positive cells (B) whereas tumor cells were negative for insulin (A), glucagon (C) and SRIF. This non-functioning tumor was negative for IAPP (F and H) and was also negative for insulin (E and F), glucagon (E), SRIF (G) and PP (H). (A) Insulin, (B) IAPP, (C) glucagon, (D) PP, (E) insulin/glucagon double stained, (F) IAPP/Insulin double stained, (G) SRIF, (H) IAPP/PP double immunostained.