Table II. IL-3–mediated cell cycle progression of HEK293 IL-3R–expressing cells.

	G0/G1	S	G2/M
	%	%	%
(HEK293 IL-3R) S	65.5 ± 8	27 ± 4	6.5 ± 1.5
(HEK293 IL-3R) S + IL-3	64.7 ± 7	30.5 ± 5	4.8 ± 2
(HEK293 IL-3R) FN	61 ± 3.5	30.7 ± 5	8.3 ± 4
(HEK293 IL-3R) FN + IL-3	51.6 ± 6	40.4 ± 4.5	8 ± 3

HEK293 IL-3R cells serum starved for 24 h were kept in suspension or let to adhere to FN-coated plates in the presence or absence of 20 ng/ml IL-3. After 18 h of IL-3 stimulation, the cells were fixed with ethanol and DNA was stained with propidium iodide. The fluorescence related to DNA content was evaluated by flow cytometry. The percentage of cells in each phase of the cell cycle was determined by ModFit LT Software (Verity Software House Inc.). The numbers are the mean ± SD of three different experiments done on separate days, each performed in triplicate.