Key regulator of both differentiation and survival of T-lymphocytes during thymocyte development in mammals. Essential in controlling the responsiveness of hematopoietic stem cells to chemotactic signals by modulating the expression of the receptors CCR7 and CCR9, which direct the movement of progenitor cells from the bone marrow to the thymus (PubMed:27959755). Is a regulator of IL2 promoter and enhances IL2 expression in activated CD4(+) T-lymphocytes (PubMed:16809611). Tumor-suppressor that represses transcription through direct, TFCOUP2-independent binding to a GC-rich response element (By similarity). May also function in the P53-signaling pathway (By similarity). Interacts with TFCOUP1, SIRT1, ARP1 and EAR2 (By similarity). Interacts with EP300; the interaction is detected in activated T-lymphocytes, but not under resting conditions (PubMed:27959755). Highly expressed in brain and in malignant T-cell lines derived from patients with adult T-cell leukemia/lymphoma. Sumoylated with SUMO1. The disease is caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. May be due to exon skipping.