RACGAP1 and breast cancer: To further elucidate the underlying mechanisms of potential stimulatory action of AS extract in primary breast cancer cells, the mRNA expressions of cell proliferation (cyclin D1, TOP2A, and RacGAP1) and survival (survivin) genes in eight epithelial cell-enriched primary breast cancer cell samples were determined using real-time PCR after AS (0.4–1.6 mg/mL) or 17β-estradiol (E2, 0.1 μM) treatments.