Early lymphocyte precursors are directly and selectively inhibited by estrogen in culture.

Lin⁻ c-kit^Hi BM cells were placed in serum-free, stromal cell-free cultures with or without β-estradiol (10⁻⁸M). Gr-1⁺ myeloid and CD19⁺lymphoid cells determined by flow cytometry are shown after 7 days of culture.