SS18-SSX1 condensates at H2AK119ub-marked oncogenic locus, recruits BAFs complexes and histone acetyltransferase CBP/p300 while excludes HDAC1/2 deacetylase complexes to assemble transcriptionally active chromatin loops/TADs that elevate H3K27ac level and sustain oncogene overexpression in synovial sarcoma. This evidence concerns the gene EP300 and synovial sarcoma.