Expression of IFNγ receptors (IFNγR) in neuroendocrine gastrointestinal tumor cells. mRNA expression of IFNγR was evaluated in human pancreatic carcinoid BON tumor cells (lane 3). Neuroendocrine differentiated colorectal carcinoma cells (Colo320 DM) served as positive control for IFNγR (lane 4). β-actin was used as loading control (lane 1: BON, lane 2: Colo320 DM). PCR products were visualized by gel electrophoresis on an ethidium bromide-stained agarose gel. M: 100 bp DNA ladder.