ICAM1 and peritonitis: Inflammatory cells such as lymphocytes, neutrophils, and monocytes express ICAM-119,30,61 and are either present or migrate into the peritoneal cavity after Zymosan-induced peritonitis.21 In the light of this knowledge and based on our ex vivo flow cytometry results (Fig. 7), it is reasonable to hypothesize that the increased signal observed on SPECT imaging of the left abdominal side in the animals with peritonitis is the result of ICAM-1 recognition by anti-ICAM-1-labeled MBs.