SSX2 and synovial sarcoma: Chromatin immunoprecipitation revealed a decrease in HDAC1 and H3K23me3 at the EGR1 promoter, a known target for repression by the SS18-SSX/TLE1/ATF2 complex consistent with a disruption of the biologic effects on SS18-SSX target genes in synovial sarcoma (Figure 6E) [5, 7, 8].