Fig. 2.

Reversible reduction of cell proliferation rate in SFM or PFM. A, Growth curve of CAD cells. Cells were grown in serum-containing medium; on day 0 (D0), they were changed into SFM or PFM or maintained in serum-containing medium for an additional 4 d. Values are the average of the cell number from four separate experiments. The cell number was obtained as described in Materials and Methods. B, Differentiated CAD cells resumed proliferation after serum addition. CAD cells were maintained in SFM or PFM for 4 d, after which FBS was added to a final concentration of 8% to the culture medium.Arrowhead indicates serum addition. Error bars indicate SEM (n = 4). Note: some of the error bars are too small to be visible.