Cell proliferation was monitored by the [3H]-thymidine incorporation assay (A), after synchronization with serum starvation, followed by consecutive treatments with 100 nmol/L 17β-estradiol and progesterone both for 24 hours.*E+Alu versus CP-Alu (P = 0.002), and #E+Alu versus E-Alu #(P = 0.0001). Similar hormonal stimuli were used to monitor cell counting (B): 6-well plates were seeded with 5 × 103 cells at day 0 and counted again after treatment. Electronic cell counts were performed in triplicate. Cell cycle analysis (C) showed progression of E+Alu (in relation to CP-Alu and E-Alu) throughout the cell cycle into S and G2/M phases. *E+Alu versus CP-Alu (P = 0.01), and #E+Alu versus E-Alu (P = 0.04). G0/G1 (aP = 0.07, bP = 0.15), S (cP = 0.001, dP = 0.01), and G2/M (eP = 0.05, fP = 0.14).