Appears to function synergistically with RBM14 as a transcriptional coactivator. Isoform 1 and isoform 2 function in nuclear receptor coactivation. Isoform 1 and isoform 2 function in general transcriptional coactivation. 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). Interacts with MLLT10. Isoform 1 interacts with RBM14 isoform 1. Isoform 2 interacts with RBM14 isoform 1. Component of the multiprotein chromatin-remodeling complexes SWI/SNF: SWI/SNF-A (BAF), SWI/SNF-B (PBAF) and related complexes. The canonical complex contains a catalytic subunit (either SMARCA4/BRG1/BAF190A or SMARCA2/BRM/BAF190B) and at least SMARCE1, ACTL6A/BAF53, SMARCC1/BAF155, SMARCC2/BAF170, and SMARCB1/SNF5/BAF47. Other subunits specific to each of the complexes may also be present permitting several possible combinations developmentally and tissue specific. Component of the SWI/SNF (GBAF) subcomplex, which includes at least BICRA or BICRAL (mutually exclusive), BRD9, SS18, the core BAF subunits, SMARCA2/BRM, SMARCA4/BRG1/BAF190A, ACTL6A/BAF53, SMARCC1/BAF155, and SMARCD1/BAF60A (PubMed:29374058). Fairly ubiquitously expressed. Expressed in synovial sarcomas and in other human cell lines. The fusion genes SSXT-SSX1 and SSXT-SSX2 are expressed only in synovial sarcomas. A chromosomal aberration involving SS18 may be a cause of synovial sarcoma. Translocation t(X;18)(p11.2;q11.2). The translocation is specifically found in more than 80% of synovial sarcoma. The fusion products SSXT-SSX1 or SSXT-SSX2 are probably responsible for transforming activity. Heterogeneity in the position of the breakpoint can occur (low frequency). Belongs to the SS18 family. Extended N-terminus. Extended N-terminus.