A, pcDNA- and PELP1-expressing clones were cultured in 5% DCC serum for 48 h and treated with or without E2 for 72 h, and the cell number was determined. B, pcDNA and PELP1 clones were serum-starved in 0% DCC serum for 48 h and treated with E2 for 20 h, and the cell cycle status was analyzed by flow cytometry. A representative figure from fluorescence-activated cell sorter analysis is shown here. C, the bar graphs show the percentages of cells in S phase. **, p < 0.01; ***, p < 0.001; NS, non-significant (Student’s t test). Each value represents an average of three experiments. D, pcDNA and PELP1 clones were treated with or without E2 for 20 h, and CDK2 kinase activity was determined in an in vitro kinase assay with histone H1 as a substrate.