To determine the relevance of our in vitro findings in vivo, we evaluated the macrophage infiltrate in a pituitary-specific Aip-knockout mice AipFlox/Flox;Hesx1Cre/+ who develop GH-secreting pituitary tumors with disruption of the reticulin network (detailed description of this animal model will be reported separately). The gene discussed is GH1; the disease is pituitary tumor.