Inhibition of Bcl3 gene expression mediates the anti-proliferative action of estrogen in pituitary lactotrophs in primary culture

► We investigated how estrogen inhibited the proliferation of pituitary lactotrophs. ► DNA microarray analysis identified Bcl3 as an estrogen-downregulated gene. ► Overexpression of Bcl3 blocked the antiproliferative action of estrogen. ► Bcl3 is implicated in the antiproliferative action of estrogen on lactotrophs.