In order to test whether GM-CSF in the AIP peritoneum was acting directly via its receptor on the incoming monocytes, Csf2rb-/-Csf2rb2-/- (CD45.2) donor monocytes (CD115+) were injected i.p. at day 2 into C57BL/6 WT (CD45.1) mice undergoing AIP. The gene discussed is CSF2RBP1; the disease is autoimmune pancreatitis.