HDAC9 and synovial sarcoma: Consistent with previous reports demonstrating the activity of HDAC inhibitors in synovial sarcomas, several HDAC inhibitors had significant activity in this PDC when normalised with normal mesenchymal controls (Fig. 4e, green dots and supplementary Figure 2); however, they showed toxicity for the bone marrow cell controls (low sDSS bone marrow controls).