The function of BRD9 (bromodomain containing 9, ENSG00000028310) is as follows. Plays a role in chromatin remodeling and regulation of transcription (PubMed:22464331, PubMed:26365797). Acts as a chromatin reader that recognizes and binds acylated histones: binds histones that are acetylated and/or butyrylated (PubMed:26365797). Component of SWI/SNF chromatin remodeling subcomplex GBAF that carries out key enzymatic activities, changing chromatin structure by altering DNA- histone contacts within a nucleosome in an ATP-dependent manner (PubMed:29374058). Also orchestrates the RAD51-RAD54 complex formation and thereby plays a role in homologous recombination (HR) (PubMed:32457312). {ECO:0000269|PubMed:22464331, ECO:0000269|PubMed:26365797, ECO:0000269|PubMed:29374058, ECO:0000269|PubMed:32457312}.