Functional granulocyte/macrophage colony stimulating factor receptor is constitutively expressed on neoplastic plasma cells and mediates tumour cell longevity. Posted byadmin 27. July 1998 Villunger A, Egle A, Kos M, Egle D, Tinhofer I, Henn T, Uberall F, Maly K, Greil R. http://www.ncbi.nlm.nih.gov/pubmed/9734660