“…BM cells were cul-Lured in 35 x 10 mm dishes using a modification of the technique previously described (Yang et al 1986;Sieff et al 1987). 5 x 104 to 2 x 105 non-adherent BM mononuclear cells were prated in 1 ml of Iscove's modified Dulbecco's medium (IMDM, Gibco Laboratories), clntaining 0.9% methylcelulose, 30% FCS, 1% bovine serum albumin (BSA, Sigma Chemical Co., Ltd. St. Louis, Mo, USA), 2 X 10-s M 2-mercaptoethanol (2ME, Bio-Rad Laboratories, Richmonds, CA USA), 100 colony forming units (CFU) /ml of human recombinant interleukin 3 (IL3, Genzyme Corp., Boston, MA, USA), and 2 U/ml of human recombinant erythropoietin (EPO, Chugai Pharmaceutical Co. Ltd., Tokyo).…”