This resulted in the abrogation of the effects of estradiol on tumor-infiltrating Treg cells (CD4+CD25highCD127low) and the concomitant destruction of ERα and suppression of FOXP3 expression to terminate the suppressive effects of Tregs on both CD8+ and CD4+(CD4+CD25int) effector T cell subsets [222,261]. This evidence concerns the gene ESR1 and neoplasm.