Araliadiol (20-80 μM; 0-48 hours; MCF-7 cells) treatment inhibits cell cycle progression of MCF-7 at the G1-S transition. Araliadiol (20-80 μM; 0-48 hours; MCF-7 cells) treatment inhibits phosphorylation of retinoblastoma protein (Rb) in MCF-7 cells, accompanies by a decrease in the levels of cyclin D3 and cdk4 and an increase in the expression of p21 (WAF-1/Cip1).