In this task, you are given an abstract of article. Your task is to generate title for this article. Preferred titles are under thirty words.

Input: Consider Input: Regulatory T (Treg) cells, whose differentiation and function are controlled by X chromosome-encoded transcription factor Foxp3, are generated in the thymus (tTreg) and extrathymically (peripheral, pTreg), and their deficiency results in fatal autoimmunity. Here, we demonstrate that a Foxp3 enhancer, conserved noncoding sequence 1 (CNS1), essential for pTreg but dispensable for tTreg cell generation, is present only in placental mammals. CNS1 is largely composed of mammalian-wide interspersed repeats (MIR) that have undergone retrotransposition during early mammalian radiation. During pregnancy, pTreg cells specific to a model paternal alloantigen were generated in a CNS1-dependent manner and accumulated in the placenta. Furthermore, when mated with allogeneic, but not syngeneic, males, CNS1-deficient females showed increased fetal resorption accompanied by increased immune cell infiltration and defective remodeling of spiral arteries. Our results suggest that, during evolution, a CNS1-dependent mechanism of extrathymic differentiation of Treg cells emerged in placental animals to enforce maternal-fetal tolerance.

Output: Extrathymic Generation of Regulatory T Cells in Placental Mammals Mitigates Maternal-Fetal Conflict

Input: Consider Input: The origins of the mesenchymal cells participating in tissue repair and pathological processes, notably tissue fibrosis, tumor invasiveness, and metastasis, are poorly understood. However, emerging evidence suggests that epithelial-mesenchymal transitions (EMTs) represent one important source of these cells. As we discuss here, processes similar to the EMTs associated with embryo implantation, embryogenesis, and organ development are appropriated and subverted by chronically inflamed tissues and neoplasias. The identification of the signaling pathways that lead to activation of EMT programs during these disease processes is providing new insights into the plasticity of cellular phenotypes and possible therapeutic interventions.

Output: The basics of epithelial-mesenchymal transition.

Input: Consider Input: Estrogens are key regulators of growth, differentiation, and the physiological functions of a wide range of target tissues, including the male and female reproductive tracts, breast, and skeletal, nervous, cardiovascular, digestive and immune systems. The majority of these biological activities of estrogens are mediated through two genetically distinct receptors, ERalpha and ERbeta, which function as hormone-inducible transcription factors. Over the past decade, it has become increasingly clear that the recruitment of coregulatory proteins to ERs is required for ER-mediated transcriptional and biological activities. These "coactivator" complexes enable the ERs to respond appropriately: 1) to hormones or pharmacological ligands, 2) interpret extra- and intra-cellular signals, 3) catalyze the process of chromatin condensation and 4) to communicate with the general transcription apparatus at target gene promoters. In addition to activating proteins, the existence of corepressors, proteins that function as negative regulators of ER activity in either physiological or pharmacological contexts, provides an additional level of complexity in ER action. This review also describes current efforts aimed at developing pharmaceutical agents that target ER-cofactor interactions as therapeutics for estrogen-associated pathologies.
Output: Coregulators in nuclear estrogen receptor action: from concept to therapeutic targeting.