Transcription factor (PubMed:16704730, PubMed:29606353). Associated with the BAF SWI/SNF chromatin remodeling complex (PubMed:23644491, PubMed:39607926). 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, PubMed:39423807). 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:26375765, PubMed:29606353, PubMed:39423807, PubMed:39607926). 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). {ECO:0000250|UniProtKB:Q9QYE3, ECO:0000269|PubMed:16704730, ECO:0000269|PubMed:23644491, ECO:0000269|PubMed:29606353, ECO:0000269|PubMed:39423807, ECO:0000269|PubMed:39607926, ECO:0000303|PubMed:26375765, ECO:0000303|PubMed:27453576}. This is the function of BCL11A (BCL11 transcription factor A, ENSG00000119866).