SSX2 and synovial sarcoma: Since we could not detect notable differences between SS18 and its oncogenic fusion products at the proteomic level, the oncogenic activity of the SS18-SSX fusions may have to be sought either at the level of SWI/SNF (dis)assembly dynamics, post-translational modifications or an affinity for specific genomic loci [42], [106], [122], although it is formally possible that the SS18-SSX oncofusion proteins undergo different proteomic interactions in the elusive synovial sarcoma precursor cell type than those we detected in Hek293 cells [123].