Discusses research being done on the role of endoplasmic reticulum (ER) in phagosome formation in macrophages. Reference to study by E. Gagnon et al, published in a 2002 issue of the journal "Cell"; Method used to confirm the role of ER membrane protein calnexin in the phagosome membrane; Kinetics of calnexin association with phagocytic structures; Effect of phosphatidylinositol 3-kinase inhibitors on ER-mediated phagocytosis in macrophages.