Transcription factor (PubMed:16704730, PubMed:29606353). Associated with the BAF SWI/SNF chromatin remodeling complex (PubMed:23644491). Binds to the 5'-TGACCA-3' sequence motif in regulatory regions of target genes, including a distal promoter of the HBG1 hemoglobin subunit gamma-1 gene (PubMed:29606353). Involved in regulation of the developmental switch from gamma- to beta-globin, probably via direct repression of HBG1; hence indirectly repressing fetal hemoglobin (HbF) level (PubMed:29606353, PubMed:26375765). Involved in brain development (PubMed:27453576). May play a role in hematopoiesis (By similarity). Essential factor in lymphopoiesis required for B-cell formation in fetal liver (By similarity). May function as a modulator of the transcriptional repression activity of NR2F2 (By similarity). Interacts with NR2F1, PIAS3, NR2F2 and NR2F6 (By similarity). Isoform 1, isoform 2 and isoform 3 form homodimers and heterodimers (PubMed:27453576). Isoform 2 interacts with TBR1 (PubMed:30250039). Associates with the nuclear body. Colocalizes with SUMO1 and SENP2 in nuclear speckles (By similarity). Colocalizes with BCL6 in nuclear paraspeckles. Predominantly localized in the nucleus in nuclear paraspeckles. Predominantly localized in the cytoplasm in the absence of interaction with isoform 1 and isoform 2. In presence of isoform 1 or isoform 2, translocates from the cytoplasm into nuclear paraspeckles. Expressed at high levels in brain, spleen thymus, bone marrow and testis. Expressed in CD34-positive myeloid precursor cells, B-cells, monocytes and megakaryocytes. Expression is tightly regulated during B-cell development. Expressed in fetal and adult brain, and in the plasmacytoid dendritic cell. The N-terminus is involved in protein dimerization and in transactivation of transcription. The C-terminus of isoform 2 is necessary for isoform 2 interaction with TBR1. Zinc finger domains are necessary for sequence-specific binding to DNA. Sumoylated with SUMO1. Genetic variation in BCL11A underlies the fetal hemoglobin quantitative trait locus 5 [MIM:142335]. It is associated with quantitative variation in the production of F cells, that is erythrocytes containing measurable amounts of fetal hemoglobin (HbF). In healthy adults, HbF is present at residual levels (less than 0.6% of total hemoglobin) with over twenty-fold variation. Ten to fifteen percent of adults in the upper tail of the distribution have HbF levels between 0.8% and 5.0%, a condition referred to as heterocellular hereditary persistence of fetal hemoglobin (hHPFH). Although these HbF levels are modest in otherwise healthy individuals, interaction of hHPFH with beta thalassemia or sickle cell disease can increase HbF output in these individuals to levels that are clinically beneficial. Chromosomal aberrations involving BCL11A are associated with B-cell malignancies. Translocation t(2;14)(p13;q32.3) causes BCL11A deregulation and overexpression. The disease is caused by variants affecting the gene represented in this entry. Truncated N-terminus.