Involved in transcriptional activation and repression of select genes by chromatin remodeling (alteration of DNA-nucleosome topology). Required for the stability of the SWI/SNF chromatin remodeling complex SWI/SNF-B (PBAF). Acts as a negative regulator of cell proliferation. {ECO:0000269|PubMed:21248752, ECO:0000303|PubMed:22952240, ECO:0000303|PubMed:26601204}. This is the function of PBRM1 (polybromo 1, ENSG00000163939).